Utility software is system software designed to help analyze, configure, optimize or maintain a computer. A single piece of utility software is usually called a utility or tool.
Utility software usually focuses on how the computer infrastructure (including the computer hardware, operating system, application software and data storage) operates. Due to this focus, utilities are often rather technical and targeted at people with an advanced level of computer knowledge - in contrast to application software, which allows users to do things like creating text documents, playing games, listening to music or viewing websites.

Utility software categories

• Anti-virus utilities scan for computer viruses.
• Backup utilities can make a copy of all information stored on a disk, and restore either the entire disk (e.g. in an event of disk failure) or selected files (e.g. in an event of accidental deletion).
• Data compression utilities output a shorter stream or a smaller file when provided with a stream or file.
• Disk checkers can scan the contents of a hard disk to find files or areas that are corrupted in some way, or were not correctly saved, and eliminate them for a more efficiently operating hard drive.
• Disk cleaners can find files that are unnecessary to computer operation, or take up considerable amounts of space. Disk cleaner helps the user to decide what to delete when their hard disk is full.
• Disk compression utilities can transparently compress/uncompress the contents of a disk, increasing the capacity of the disk.
• Disk defragmenters can detect computer files whose contents are broken across several locations on the hard disk, and move the fragments to one location to increase efficiency.
• Disk partitions can divide an individual drive into multiple logical drives, each with its own file system which can be mounted by the operating system and treated as an individual drive.
• Disk space analyzers for the visualization of disk space usage by getting the size for each folder (including sub folders) & files in folder or drive. showing the distribution of the used space.
• Disk storage utilities
•  Archive utilities output a stream or a single file when provided with a directory or a set of files. Archive utilities, unlike archive suites, usually do not include compression or encryption capabilities. Some archive utilities may even have a separate un-archive utility for the reverse operation.
•  File managers provide a convenient method of performing routine data management tasks, such as deleting, renaming, cataloging, uncataloging, moving, copying, merging, generating and modifying data sets.
• Cryptographic utilities encrypt and decrypt streams and files.
• Hex editors directly modify the text or data of a file. These files could be data or an actual program.
• Memory testers check for memory failures.
• Network utilities analyze the computer's network connectivity, configure network settings, check data transfer or log events.
• Registry cleaners clean and optimize the Windows registry by removing old registry keys that are no longer in use.
• Screensavers were desired to prevent phosphor burn-in on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer is not in use. Contemporary screensavers are used primarily for entertainment or security.
• System monitors for monitoring resources and performance in a computer system.
• System profilers provide detailed information about the software installed and hardware attached to the computer.

Technology

Technology is the usage and knowledge of tools, techniques, crafts, systems or methods of organization in order to solve a problem or serve some purpose. The word technology comes from Greekτεχνολογία (technología); from τέχνη (téchnē), meaning "art, skill, craft", and -λογία (-logía), meaning "study of-".The term can either be applied generally or to specific areas: examples include constructi on technology, medical technology, and information technology.

Technologies significantly affect human as well as other animal species' ability to control and adapt to their natural environments. The human species' use of technology began with the conversion of natural resources into simple tools. The prehistorical discovery of the ability to control fire increased the available sources of food and the invention of the wheel helped humans in travelling in and controlling their environment. Recent technological developments, including the printing press, the telephone, and the Internet, have lessened physical barriers to communication and allowed humans to interact freely on a global scale. However, not all technology has been used for peaceful purposes; the development of weapons of ever-increasing destructive power has progressed throughout history, from clubs to nuclear weapons.

Technology has affected society and its surroundings in a number of ways. In many societies, technology has helped develop more advanced economies (including today's global economy) and has allowed the rise of a leisure class. Many technological processes produce unwanted by-products, known as pollution, and deplete natural resources, to the detriment of the Earth and its environment. Various implementations of technology influence the values of a society and new technology often raises new ethical questions. Examples include the rise of the notion of efficiency in terms of human productivity, a term originally applied only to machines, and the challenge of traditional norms.

Philosophical debates have arisen over the present and future use of technology in society, with disagreements over whether technology improves the human condition or worsens it. Neo-Luddism, anarcho-primitivism, and similar movements criticise the pervasiveness of technology in the modern world, opining that it harms the environment and alienates people; proponents of ideologies such as transhumanism and techno-progressivism view continued technological progress as beneficial to society and the human condition. Indeed, until recently, it was believed that the development of technology was restricted only to human beings, but recent scientific studies indicate that other primates and certain dolphin communities have developed simple tools and learned to pass their knowledge to other generations.

Science, engineering and technology

The distinction between science, engineering and technology is not always clear. Science is the reasoned investigation or study of phenomena, aimed at discovering enduring principles among elements of the phenomenal world by employing formal techniques such as the scientific method. Technologies are not usually exclusively products of science, because they have to satisfy requirements such as utility, usability and safety.

Engineering is the goal-oriented process of designing and making tools and systems to exploit natural phenomena for practical human means, often (but not always) using results and techniques from science. The development of technology may draw upon many fields of knowledge, including scientific, engineering, mathematical, linguistic, and historical knowledge, to achieve some practical result.

Technology is often a consequence of science and engineering — although technology as a human activity precedes the two fields. For example, science might study the flow of electrons in electrical conductors, by using already-existing tools and knowledge. This new-found knowledge may then be used by engineers to create new tools and machines, such as semiconductors, computers, and other forms of advanced technology. In this sense, scientists and engineers may both be considered technologists; the three fields are often considered as one for the purposes of research and reference.

The exact relations between science and technology in particular have been debated by scientists, historians, and policymakers in the late 20th century, in part because the debate can inform the funding of basic and applied science. In the immediate wake of World War II, for example, in the United States it was widely considered that technology was simply "applied science" and that to fund basic science was to reap technological results in due time. An articulation of this philosophy could be found explicitly in Vannevar Bush's treatise on postwar science policy, Science—The Endless Frontier: "New products, new industries, and more jobs require continuous additions to knowledge of the laws of nature... This essential new knowledge can be obtained only through basic scientific research." In the late-1960s, however, this view came under direct attack, leading towards initiatives to fund science for specific tasks (initiatives resisted by the scientific community). The issue remains contentious—though most analysts resist the model that technology simply is a result of scientific research

Utility Computing

Utility Computing is the packaging of computing resources, such as computation, storage and services, as a metered service similar to a traditional public utility (such as electricity, water, natural gas, or telephone network). This model has the advantage of a low or no initial cost to acquire computer resources; instead, computational resources are essentially rented - turning what was previously a need to purchase products (hardware, software and network bandwidth) into a service. This repackaging of computing services became the foundation of the shift to "On Demand"computing, Software as a Service and Cloud Computing models that further propagated the idea of computing, application and network as a service.There was some initial skepticism about such a significant shift.

However, the new model of computing caught and eventually became mainstream with the publication of Nick Carr's book "The Big Switch". IBM, HP and Microsoft were early leaders in the new field of Utility Computing with their business units and researchers working on the architecture, payment and development challenges of the new computing model. Google, Amazon and others started to take the lead in 2008, as they established their own utility services for computing, storage and applications.

Utility Computing can support grid computing which has the characteristic of very large computations or a sudden peaks in demand which are supported via a large number of computers.

"Utility computing" has usually envisioned some form of virtualization so that the amount of storage or computing power available is considerably larger than that of a single time-sharing computer. Multiple servers are used on the "back end" to make this possible. These might be a dedicated computer cluster specifically built for the purpose of being rented out, or even an under-utilized supercomputer. The technique of running a single calculation on multiple computers is known as distributed computing.

The term "grid computing" is often used to describe a particular form of distributed computing, where the supporting nodes are geographically distributed or cross administrative domains. To provide utility computing services, a company can "bundle" the resources of members of the public for sale, who might be paid with a portion of the revenue from clients.

One model, common among volunteer computing applications, is for a central server to dispense tasks to participating nodes, on the behest of approved end-users (in the commercial case, the paying customers). Another model, sometimes called the Virtual Organization (VO),[citation needed] is more decentralized, with organizations buying and selling computing resources as needed or as they go idle.The definition of "utility computing" is sometimes extended to specialized tasks, such as web services.

Personal computer hardware

personal computer is made up of multiple physical components of computer hardware, upon which can be installed a system software called operating system and a multitude of software applications to perform the operator's desired functions.Though a PC comes in many different forms, a typical personal computer consists of a case or chassis in a tower shape (desktop), containing components such as a motherboard.

Motherboard

The motherboard is the main component inside the case. It is a large rectangular board with integrated circuitry that connects the rest of the parts of the computer including the CPU, the RAM, the disk drives (CD, DVD, hard disk, or any others) as well as any peripherals connected via the ports or the expansion slots.

Components directly attached to the motherboard include:

• The central processing unit (CPU) performs most of the calculations which enable a computer to function, and is sometimes referred to as the "brain" of the computer. It is usually cooled by a heat sink and fan.
• The chip set mediates communication between the CPU and the other components of the system, including main memory.
• RAM (Random Access Memory) stores resident part of the current running OS (OS core and so on) and all running processes (applications parts, using CPU or input/output (I/O) channels or waiting for CPU or I/O channels).
• The BIOS includes boot firmware and power management. The Basic Input Output System tasks are handled by operating system drivers.
• Internal Buses connect the CPU to various internal components and to expansion cards for graphics and sound.
  • Current
    • The north bridge memory controller, for RAM and PCI Express
    • PCI Express, for expansion cards such as graphics and physics processors, and high-end network interfaces
    • PCI, for other expansion cards
    • SATA, for disk drives
    • ATA
  • Obsolete
    • AGP (superseded by PCI Express)
    • VLB VESA Local Bus (superseded by AGP)
    • ISA (expansion card slot format obsolete in PCs, but still used in industrial computers)

• External Bus Controllers support ports for external peripherals. These ports may be controlled directly by the south bridge I/O controller or based on expansion cards attached to the motherboard through the PCI bus.
  • USB
  • FireWire
  • eSATA
  • SCSI

Power supply

A power supply unit (PSU) converts alternating current (AC) electric power to low-voltage DC power for the internal components of the computer. Some power supplies have a switch to change between 230 V and 115 V. Other models have automatic sensors that switch input voltage automatically, or are able to accept any voltage between those limits. Power supply units used in computers are nearly always switch mode power supplies (SMPS). The SMPS provides regulated direct current power at the several voltages required by the motherboard and accessories such as disk drives and cooling fans

Removable media devices

• CD (compact disc) - the most common type of removable media, suitable for music and data.

• CD-ROM Drive - a device used for reading data from a CD.
• CD Writer - a device used for both reading and writing data to and from a CD.
• DVD (digital versatile disc) - a popular type of removable media that is the same dimensions as a CD but stores up to 12 times as much information. It is the most common way of transferring digital video, and is popular for data storage.
  • DVD-ROM Drive - a device used for reading data from a DVD.
  • DVD Writer - a device used for both reading and writing data to and from a DVD.
  • DVD-RAM Drive - a device used for rapid writing and reading of data from a special type of DVD.
• Blu-ray Disc - a high-density optical disc format for data and high-definition video. Can store 70 times as much information as a CD.
  • BD-ROM Drive - a device used for reading data from a Blu-ray disc.
  • BD Writer - a device used for both reading and writing data to and from a Blu-ray disc.
• HD DVD - a discontinued competitor to the Blu-ray format.
• Floppy disk - an outdated storage device consisting of a thin disk of a flexible magnetic storage medium. Used today mainly for loading RAID drivers.
• Iomega Zip drive - an outdated medium-capacity removable disk storage system, first introduced by Iomega in 1994.
• USB flash drive - a flash memory data storage device integrated with a USB interface, typically small, lightweight, removable, and rewritable. Capacities vary, from hundreds of megabytes (in the same ballpark as CDs) to tens of gigabytes (surpassing, at great expense, Blu-ray discs).
• Tape drive - a device that reads and writes data on a magnetic tape, used for long term storage and backups.

Secondary storage

Hardware that keeps data inside the computer for later use and remains persistent even when the computer has no power.

• Hard disk - for medium-term storage of data.
• Solid-state drive - a device similar to hard disk, but containing no moving parts and stores data in a digital format.
• RAID array controller - a device to manage several internal or external hard disks and optionally some peripherals in order to achieve performance or reliability improvement in what is called a RAID array.

Sound card

Enables the computer to output sound to audio devices, as well as accept input from a microphone. Most modern computers have sound cards built-in to the motherboard, though it is common for a user to install a separate sound card as an upgrade. Most sound cards, either built-in or added, have surround sound capabilities.

Input and output peripherals

Input and output devices are typically housed externally to the main computer chassis. The following are either standard or very common to many computer systems

Input

• input devices
  

• Keyboard - a device to input text and characters by depressing buttons (referred to as keys or buttons).
• Pointing devices
• Mouse - a pointing device that detects two dimensional motion relative to its supporting surface.
• Optical Mouse - uses light to determine mouse motion.
• Trackball - a pointing device consisting of an exposed protruding ball housed in a socket that detects rotation about two axes.
• Touchscreen - senses the user pressing directly on the display

• Gaming devices
  • Joystick - a control device that consists of a handheld stick that pivots around one end, to detect angles in two or three dimensions and reports its angle or direction to the device it is controlling.
  • Game pad - a hand held game controller that relies on the digits (especially thumbs) to provide input.
  • Game controller - a specific type of controller specialized for certain gaming purposes.
• Image, Video input devices
  • Image scanner - a device that provides input by analyzing images, printed text, handwriting, or an object.
  • Web cam - a video camera used to provide visual input that can be easily transferred over the internet.
• Audio input devices
  • Microphone - an acoustic sensor that provides input by converting sound into electrical signals.

Computer software, or just software, is a collection of computer programs and related data that provide the instructions telling a computer what to do and how to do it. We can also say software refers to one or more computer programs and data held in the storage of the computer for some purposes. In other words software is a set of programs, procedures, algorithms and its documentation. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast to the old term hardware (meaning physical devices). In contrast to hardware, software is intangible, meaning it "cannot be touched".Software is also sometimes used in a more narrow sense, meaning application software only. Sometimes the term includes data that has not traditionally been associated with computers, such as film, tapes, and records.

Examples of computer software include:

• Application software includes end-user applications of computers such as word processors or video games, and ERP software for groups of users.
• Middleware controls and co-ordinates distributed systems.
• Programming languages define the syntax and semantics of computer programs. For example, many mature banking applications were written in the COBOL language, originally invented in 1959. Newer applications are often written in more modern programming languages.
• System software includes operating systems, which govern computing resources. Today large applications running on remote machines such as Websites are considered to be system software, because the end-user interface is generally through a graphical user interface, such as a web browser.
• Testware is software for testing hardware or a software package.
• Firmware is low-level software often stored on electrically programmable memory devices. Firmware is given its name because it is treated like hardware and run ("executed") by other software programs.
• Shrinkware is the older name given to consumer-purchased software, because it was often sold in retail stores in a shrink-wrapped box.
• Device drivers control parts of computers such as disk drives, printers, CD drives, or computer monitors.
• Programming tools help conduct computing tasks in any category listed above. For programmers, these could be tools for debugging or reverse engineering older legacy systems in order to check source code compatibility.

Practical computer systems divide software systems into three major classes[citation needed]: system software, programming software and application software, although the distinction is arbitrary, and often blurred.

System software

System software provides the basic functions for computer usage and helps run the computer hardware and system. It includes a combination of the following:

• Device drivers
• Operating systems
• Servers
• Utilities
• Window systems

System software is responsible for managing a variety of independent hardware components, so that they can work together harmoniously. Its purpose is to unburden the application software programmer from the often complex details of the particular computer being used, including such accessories as communications devices, printers, device readers, displays and keyboards, and also to partition the computer's resources such as memory and processor time in a safe and stable manner.

Programming software

software usually provides tools to assist a programmer in writing computer programs, and software using different programming languages in a more convenient way. The tools include:

• Compilers
• Debuggers
• Interpreters
• functions..

Application software

• Application software is developed to aid in any task that benefits from computation. It is a broad category, and encompasses software of many kinds, including the internet browser being used to display this page. This category includes:Linkers
• Text editors

An Integrated development environment (IDE) is a single application that attempts to manage all these 

• Business software
• Databases
• Decision making software
• Educational software
• Image editing
• Industrial automation
• Mathematical software
• Medical software
• Molecular modeling software
• Quantum chemistry and solid state physics software
• Simulation software
• Spreadsheets
• Telecommunications
• Video games
• Word processing