For other uses, see Bitmap (disambiguation).

In computing, a bitmap is a mapping from some domain (for example, a range of integers) to bits, that is, values which are zero or one. It is also called a bit array or bitmap index.

Bitmap image downsampled from an Inkscape vectorial image

In computer graphics, when the domain is a rectangle (indexed by two coordinates) a bitmap gives a way to store a binary image, that is, an image in which each pixel is either black or white (or any two colors).

The more general term pixmap refers to a map of pixels, where each one may store more than two colors, thus using more than one bit per pixel. Often bitmap is used for this as well. In some contexts, the term bitmap implies one bit per pixel, while pixmap is used for images with multiple bits per pixel.^[1][2]

A bitmap is a type of memory organization or image file format used to store digital images. The term bitmap comes from the computer programming terminology, meaning just a map of bits, a spatially mapped array of bits. Now, along with pixmap, it commonly refers to the similar concept of a spatially mapped array of pixels. Raster images in general may be referred to as bitmaps or pixmaps, whether synthetic or photographic, in files or memory.

Many graphical user interfaces use bitmaps in their built-in graphics subsystems;^[3] for example, the Microsoft Windows and OS/2 platforms' GDI subsystem, where the specific format used is the Windows and OS/2 bitmap file format, usually named with the file extension of .BMP (or .DIB for device-independent bitmap). Besides BMP, other file formats that store literal bitmaps include InterLeaved Bitmap (ILBM), Portable Bitmap (PBM), X Bitmap (XBM), and Wireless Application Protocol Bitmap (WBMP). Similarly, most other image file formats, such as JPEG, TIFF, PNG, and GIF, also store bitmap images (as opposed to vector graphics), but they are not usually referred to as bitmaps, since they use compressed formats internally.

binary

In mathematics and digital electronics, a binary number is a number expressed in the binary numeral system or base-2 numeral system which represents numeric values using two different symbols: typically 0 (zero) and 1 (one). The base-2 system is apositional notation with a radix of 2. Because of its straightforward implementation in digital electronic circuitry using logic gates, the binary system is used internally by almost all modern computers and computer-based devices. Each digit is referred to as a bit.

For other uses, see Baud (disambiguation).

In telecommunication and electronics, baud (/ˈbɔːd/, unit symbol Bd) is the unit for symbol rate or modulation rate in symbols per second or pulses per second. It is the number of distinct symbol changes (signaling events) made to the transmission medium per second in a digitally modulated signal or a line code.

Digital data modem manufacturers commonly define the baud as the modulation rate of data transmission and express it as bits per second.^[1]

Baud is related to gross bit rate expressed as bits per second.

This article is about the concept in computing and networking. For use in signal and wireless communications, see Bandwidth (signal processing). For other uses, seeBandwidth (disambiguation).

In computing, bandwidth is the bit-rate of available or consumed information capacity expressed typically in metric multiples of bits per second. Variously, bandwidth may be characterized as network bandwidth,^[1] data bandwidth,^[2] or digital bandwidth.^[3][4]

This definition of bandwidth is in contrast to the field of signal processing, wireless communications, modem data transmission, digital communications, and electronics, in whichbandwidth is used to refer to analog signal bandwidth measured in hertz, meaning the frequency range between lowest and highest attainable frequency while meeting a well-defined impairment level in signal power.

However, the actual bit rate that can be achieved depends not only on the signal bandwidth, but also on the noise on the channel.

For other uses, see Archive (disambiguation).

For the Wikipedia coordination point on archived pages, see Wikipedia:Historical archive.

For details on how to archive a talk page, see Help:Archiving a talk page.

"Digital archive" redirects here. It is not to be confused with Digital library. For other uses, see digital archiving.

Shelved record boxes of an archive.

An archive is an accumulation of historical records or the physical place they are located.^[1] Archives contain primary source documents that have accumulated over the course of an individual or organization's lifetime, and are kept to show the function of that person or organization. Professional archivists and historians generally understand archives to be records that have been naturally and necessarily generated as a product of regular legal, commercial, administrative or social activities. They have been metaphorically defined as "the secretions of an organism",^[2] and are distinguished from documents that have been consciously written or created to communicate a particular message to posterity.

In general, archives consist of records that have been selected for permanent or long-term preservation on grounds of their enduring cultural, historical, or evidentiary value. Archival records are normally unpublished and almost always unique, unlike books or magazines for which many identical copies exist. This means that archives are quite distinct from libraries with regard to their functions and organization, although archival collections can often be found within library buildings.^[3]

A person who works in archives is called an archivist. The study and practice of organizing, preserving, and providing access to information and materials in archives is calledarchival science. The physical place of storage can be referred to as an archive (more usual in the UK), an archives (more usual in the USA), or a repository.^[4]

When referring to historical records or the places they are kept, the plural form archives is chiefly used.^[5] The computing use of the term 'archive' should not be confused with the record-keeping meaning of the term.

applet

In computing, an applet is any small application that performs one specific task that runs within the scope of a dedicated widget engine or a larger program, often as a plug-in.^[1][2] The term is frequently used to refer to a Java applet, a program written in the Java programming language that is designed to be placed on a web page. Applets are typical examples of transient and auxiliary applications that don't monopolize the user's attention. Applets are not full-featured application programs, and are intended to be easily accessible.



credited by owner 

anti virus

Antivirus" redirects here. For the antiviral medication, see Antiviral drug.

ClamTk, an open source antivirus based on theClamAV antivirus engine, originally developed by Tomasz Kojm in 2001.

Antivirus or anti-virus software (often abbreviated as AV), sometimes known as anti-malware software, is computer software used to prevent, detect and remove malicious software.

Antivirus software was originally developed to detect and remove computer viruses, hence the name. However, with the proliferation of other kinds of malware, antivirus software started to provide protection from other computer threats. In particular, modern antivirus software can protect from: malicious Browser Helper Objects (BHOs), browser hijackers,ransomware, keyloggers, backdoors, rootkits, trojan horses, worms, malicious LSPs, dialers, fraudtools, adware andspyware.^[1] Some products also include protection from other computer threats, such as infected and malicious URLs, spam,scam and phishing attacks, online identity (privacy), online banking attacks, social engineering techniques, Advanced 

credited by owner