DB25 plugs The DB25 (originally DE-25) connector is an analog 25-pin plug of the D-Subminiature connector family (D-Sub or Sub-D). As with the DB9 connector, the DB25 is mainly used for serial connections, allowing for the asynchronous ... Read more
HTML document An HTML page is a simple file containing text formatted with HTML tags. Traditionally, the file is given an .htm or .html extension, but a web page may have other extensions as well. A web page can be built from even the most ... Read more
Replay attack "Replay" attacks are "Man in the middle" attacks that involve intercepting data packets and replaying them, that is, resending them as is (with no decryption) to the receiving server. As a result, depending on the context, ... Read more
Intranet An intranet is a set of Internet services (for example a web server) inside a local network, i.e. only accessible from workstations of a local network, or rather a set of well-defined networks that are invisible (or inaccessible) ... Read more
A programming language is a language designed to describe a set of consecutive actions to be executed by a computer. A programming language is, therefore, a practical way for us humans to give instructions to a computer. Languages that ... Read more
Multichannel audio The term "multichannel audio" refers to the use of multiple audio tracks to reconstruct sound on a multi-speaker sound system. Two digits separated by a decimal point (2.1, 5.1, 6.1, 7.1, etc.) are used to classify the ... Read more
Files in MS DOS In a computers data is stored in files. When you run a program, MS-DOS processes the data stored in the file and passes it to the system. In MS-DOS a file can be any size, however the file name is more restricted, it can ... Read more
The Role of Memory The term "memory" applies to any electronic component capable of temporarily storing data. There are two main categories of memories: internal memory that temporarily memorises data while programs are running. Internal ... Read more
Lack of security Radio waves intrinsically have the power to propagate in all directions, with a relatively wide range. Because of this, it is very difficult to keep radio broadcasts confined to a limited area. Radio propagation also ... Read more
What's an RJ45 plug? A network card may have several types of connectors, with the most common being: An RJ45 connector; A BNC connector (coaxial cable). The RJ-45 is the one which interests us here, as it it the most widely used. The ... Read more
What is a hub? A hub is an element of hardware for centralising network traffic coming from multiple hosts, and to propagate the signal. The hub has a certain number of ports (it has enough ports to link machines to one another, usually 4, ... Read more
Data coding What is ASCII code? ASCII Character Chart Extended ASCII Character Chart EBCDIC code Unicode Data coding Morse code was the first code used for long-distance communication. Samuel F.B. Morse invented it in 1844. This code is ... Read more
The notion of a user Windows NT is an operating system which manages sessions, meaning that when the system is started, it is necessary to log in with a user name and password. When Windows NT is installed, the administrator account is ... Read more
The Concept of Governance The term "Governance" specifies the ability of an organization to be able to control and regulate its own operation so as to avoid conflicts of interest related to the division between beneficiaries (shareholders) ... Read more
Symmetric encryption Symmetric encryption (also called private-key encryption or secret-key encryption) involves using the same key for encryption and decryption. ... Read more
What is a Spreadsheet? A spreadsheet (or spreadsheet program) is software that permits numerical data to be used and to perform automatic calculations on numbers contained in a table. It is also possible to automate complex calculations by ... Read more
Command Description dir lists the contents of a folder cd changes folder cd .. parent folder md or mkdir creates a new folder deltree deletes a folder and all sub-folders copy, xcopy copies a file move moves a file del deletes a file type ... Read more
The role of the hard drive Structure How it works Block mode 32-bit mode Technical specifications The role of the hard drive The hard drive is the component which is used to permanently store data, as opposed to RAM, which is erased ... Read more
MKV format The MKV format (Matroska Video) is an entirely free video format. More precisely, it is a container (hence the name Matroska, in reference to the Russian dolls contained within another) making it possible to contain video (DivX, ... Read more
Substitution cipher Substitution cipher involves replacing one or more entities (generally letters) in a message with one or more other entities. There are several types of substitution cryptosystems: Monoalphabetic substitution involves ... Read more
