G. Glossary

ACL

Access Control List. An Access Control List is a list attached to an object such as a file. It consists of control expressions, each of which grants or denies some ability to a particular user or group of users.

Administration

A European public administration.

Administrators

The IT management of an Administration.

API

Application Programming Interface. The specific method prescribed by a computer operating system, application or third-party tool by which a programmer writing an application program can make requests of the operating system. Also known as Application Programmers Interface.

ASP

Active Server Pages. An HTML page that includes one or more scripts (small embedded programs) that are processed on a Microsoft Web server before the page is sent to the user. An ASP is somewhat similar to a server-side include or a common gateway interface (CGI) application in that all involve programs that run on the server, usually tailoring a page for the user.

BDC

Backup Domain Controller. Roles that can be assigned to a server in a network of computers that use the Windows NT operating system. Windows NT uses the idea of a domain to manage access to a set of network resources (applications, printers, and so forth) for a group of users. The user need only to log in to the domain to gain access to the resources, which may be located on a number of different servers in the network. One server, known as the primary domain controller, manages the master user database for the domain. One or more other servers are designated as backup domain controllers. The primary domain controller periodically sends copies of the database to the backup domain controllers. A backup domain controller can step in as primary domain controller if the PDC server fails and can also help balance the workload if the network is busy enough.

Beta Code

When software is written it goes through a number of different stages before it is considered to be sufficiently error free and functionally correct to be used as production software. The first of these stages is called alpha and the second beta. Beta Code is therefore code which is substantially correct but could still contain significant errors. It should therefore be used with caution.

Binaries

Software is usually written in a language easily understandable by humans which is called Source Code. This code is converted to a form understood directly by the computer's processor. This code is called Binary because it consists of a string of zeros and ones. This is the form in which most proprietary code is delivered and it is very difficult to convert back to a form easily understood by humans. Having source code allows changes to the software to be made and also allows people to understand what it is doing.

Concurrent User Licence.

A form of licence which charges on the basis of the maximum number of users that can access an application at once.

Boilerplate Entries

Any standard and undifferentiated chunks of data, usually stuff that has to be present but is of no great interest.

CIL

Common Intermediate Language. Compiler and machine independent intermediate code that will run by a Common Language Runtime or CLR. This code can be obtained from a number of compiled languages including C# and C. Both CIL and CLR are part of the CLI Common Language Infrastructure.

Daemon

A system related program or process that sits in the background until it is invoked by another process or some event to perform its task.

DBMS

Database Management System. A program that lets one or more computer users create and access data in a database. The DBMS manages user requests (and requests from other programs) so that users and other programs are free from having to understand where the data is physically located on storage media and, in a multi-user system, who else may also be accessing the data.

DEC Protocol

The Digital Equipment Corporation or DEC created a set of protocols for controlling terminal devices. These protocols have become widely used and are now standards.

DHCP

Dynamic Host Configuration Protocol. A communications protocol that lets network administrators manage centrally and automate the assignment of Internet Protocol (IP) addresses in an organisation's network.

Distribution

For open source software such as Linux, companies such as Red Hat specialise in packaging components from many sources together into a single package or set of packages that can be distributed conveniently to users as a single download or on a set of CDs.

DNS

Domain Name Server. Used to convert between the name of machine on the Internet and its numeric address.

Domain (Authentication)

A set of authorisation identifiers (people and processes) managed by an authentication server.

Free Software

This is defined at http://www.gnu.org/philosophy/free-sw.html.

FTP

File Transfer Protocol. A system-independent means of transferring files between systems connected via TCP/IP. It ensures that the file is transferred correctly, even if there are errors during transmission.

Gopher Services

Early hypertext-like information retrieval system.

GPL

GNU General Public License.

Green Screen

A terminal or display that is only capable of displaying fixed-size characters and (possibly) simple block graphics. The name comes from the fact that many mainframe display screens in the 1970s and 1980s used a green phosphor.

GUI

Graphical User Interface.

Hashes

A Hash is a unique short-form identifier, a “fingerprint” of something more complicated. Hashes are produced using one-way mathematical functions. They are used in database systems and in security and cryptographic systems.

HTTP

Hypertext Transfer Protocol. A set of rules for exchanging files (text, graphic images, sound, video, and other multimedia files) on the World Wide Web. Relative to the TCP/IP suite of protocols (which are the basis for information exchange on the Internet), HTTP is an application protocol.

Java Applet

A mini software program that a Java or ActiveX enabled browser downloads and uses automatically. It can add sophisticated support for Web pages, far beyond programming such as DHTML or Javascript.

Java Servlet

A Java program that runs as part of a network service, typically on an HTTP server and responds to requests from clients. The most common use for a servlet is to extend a web server by generating web content dynamically. For example, a client may need information from a database; a servlet can be written that receives the request, gets and processes the data as needed by the client and then returns the result to the client.

JDBC

Java Database Connectivity. An application program interface (API) specification for connecting programs written in Java to the data in popular databases. The application program interface lets you encode access request statements in Structured Query Language (SQL) that are then passed to the program that manages the database. It returns the results through a similar interface.

Kernel

The core of an operating system that handles tasks such as memory allocation, device input and output, process allocation, security and user access.

LDAP

Lightweight Directory Access Protocol. A software protocol for enabling anyone to locate organisations, individuals, and other resources such as files and devices in a network, whether on the public Internet or on a internal intranet. LDAP is a "lightweight" (smaller amount of code) version of Directory Access Protocol (DAP), which is part of X.500, a standard for directory services in a network.

LGPL

GNU Lesser General Public License

Load Balancing

Load balancing is dividing the amount of work that a computer has to do between two or more processors or computers so that more work gets done in the same amount of time and, in general, all users get served faster. Load balancing can be implemented with hardware, software, or a combination of both. Typically, load balancing is the main reason for computer server clustering.

MAA

Mail Access Agent. A term used in this report to describe the server mail component which manages access to mailstore by a MUA. Examples are POP and IMAP servers. See Appendix C page 108 above for a full discussion.

MDA

Mail Delivery Agent. A mail component which accepts mail from and MTA and delivers it to mailstore.

Metadata

A definition or description of data.

MTA

Mail Transport Agent. This is the mail component with the responsibility of deciding if mail handed to it is for a local account or not. It passes local mail to an MDA or stores it directly in mailstore itself. Remote mail is passed to another MTA.

MUA

Mail User Agent. The client mail component which retrieves mail from mailstore and presents it to the user. It allows the user to create new mail and to send it to a MTA for onward transmission. Often the MUA will be associated with a graphical interface.

.NET

Microsoft's set of software technologies for connecting information, people, systems and devices. It is based on web services which are small applications that can connect to each other as well as to other larger applications over the Internet. The OSS project Mono is an implementation of the .NET development framework.

NFS

Network File Service. A protocol commonly used by Unix like systems to access files held on remote systems as if they were local.

ODBC

Open Database Connectivity. An open standard application programming interface (API) for accessing a database. By using ODBC statements in a program, you can access files in a number of different databases, including Access, dBase, DB2, Excel, and Text. In addition to the ODBC software, a separate module or driver is needed for each database to be accessed.

Open Relay

An open relay (sometimes called an insecure relay or a third-party relay) is an SMTP email server that allows third-party relay of email messages. By processing mail that is neither for nor from a local user, an open relay makes it possible for an unscrupulous sender to route large volumes of spam. In effect, the owner of the server – who is typically unaware of the problem – donates network and computer resources to the sender's purpose. In addition to the financial costs incurred when a spammer hijacks a server, an organisation may also suffer system crashes, equipment damage, and loss of business.

Open Source Software

This is defined at http://www.opensource.org/docs/definition_plain.html.

OSS

See Open Source Software.

PDA

Personal Digital Assistant. An electronic hand held computer.

PDC

Primary Domain Controller. See Backup Domain Controller (BDC).

PHP

PHP: Hypertext Preprocessor. A script language and interpreter that is freely available and used primarily on Linux Web servers. PHP is an alternative to Microsoft's Active Server Page (ASP) technology. As with ASP, the PHP script is embedded within a Web page along with its HTML. Before the page is sent to a user that has requested it, the Web server calls PHP to interpret and perform the operations called for in the PHP script.

PKI

Public Key Infrastructure. A PKI enables users of a basically insecure public network such as the Internet to securely and privately exchange data and money through the use of a public and a private cryptographic key pair that is obtained and shared through a trusted authority. The public key infrastructure provides for a digital certificate that can identify an individual or an organization and directory services that can store and, when necessary, revoke the certificates.

Potential User Licence

A form of licence which charges on the basis of the maximum number of users that have the ability access an application.

Protocol

A special set of rules that end points in a telecommunication connection use when they communicate. Protocols exist at several levels in a telecommunication connection. There are hardware telephone protocols. There are protocols between each of several functional layers and each corresponding layer at the other end of a communication. Both end points must recognise and observe a protocol. Protocols are often described in an industry or international standard.

Proxy Server

A server that acts as an intermediary between a workstation user and the Internet so that the enterprise can ensure security, administrative control, and caching service. A proxy server is associated with or part of a gateway server that separates the enterprise network from the outside network and a firewall server that protects the enterprise network from outside intrusion.

Scenario

See Section 4 for a definition.

Schema

The organisation or structure for a database. The activity of data modelling leads to a schema.

Session Manager

When a user logs on to a computer they create a session which consists of an environment full of control information personal to them, a series of processes. The manager allows the user to change this environment and can also save it so that when the user next logs on the computer is returned to the state it was before they last logged off.

Smart Card

A plastic card which contains a computer chip. The card is used for performing operations which require the data which is stored on the chip.

SMB

Server Message Block. This the protocol used in Windows networks to allow resources such as files on one machine to be shared on other machines as if they were local.

SMS

Short Message Service. A service for sending messages of up to 160 characters (224 characters if using a 5-bit mode) to mobile phones that use Global System for Mobile (GSM) communication.

Source Code

See Binaries.

SQL

Structured Query Language. A standard interactive and programming language for getting information from and updating a database. Although SQL is both an ANSI and an ISO standard, many database products support SQL with proprietary extensions to the standard language. Queries take the form of a command language that lets you select, insert, update, find out the location of data, and so forth. There is also a programming interface.

SSL

Secure Sockets Layer. A commonly-used protocol for managing the security of a message transmission on the Internet. SSL has recently been succeeded by Transport Layer Security (TLS), which is based on SSL. SSL uses a program layer located between the Internet's Hypertext Transfer Protocol (HTTP) and Transport Control Protocol (TCP) layers. SSL is included as part of both the Microsoft and Netscape browsers and most Web server products.

Stored Procedure

A set of Structured Query Language (SQL) statements with an assigned name that's stored in the database in compiled form so that it can be shared by a number of programs.

Trigger

A set of Structured Query Language (SQL) statements that automatically "fires off" an action when a specific operation, such as changing data in a table, occurs.

TLS

Transport Layer Security. A layer providing encryption and authentication services that can be negotiated during the startup phase of many Internet protocols (e.g. SMTP, LDAP, IMAP, POP3). TLS is derived from SSL and uses the same certificates but does not require each service to be given a new port number; see SSL.

VMS

An operating system developed by the Digital Equipment Corporation (DEC) for use on their VAX minicomputers. Later ported to the Alpha 64-bit system. One of the principal designers of VMS later designed the Windows NT kernel.

WebDAV

World Wide Web Distributed Authoring and Versioning. The Internet Engineering Task Force (IETF) standard for collaborative authoring on the Web: a set of extensions to the Hypertext Transfer Protocol (HTTP) that facilitates collaborative editing and file management between users located remotely from each other on the Internet.

Window Manager

In a modern graphical environment a user is presented with a series of windows which have processes running in them. This means that they can be running many different things at the same time and have the output displayed simultaneously to the screen. Managing these windows is the role of the window manager. It has to keep track of which window the user is currently interested in, allow the user to change windows and create or destroy windows. It also controls the way the windows look, their shape and control features.

XML

Extensible Markup Language. A flexible way to create common information formats and share both the format and the data on the World Wide Web, intranets, and elsewhere. XML is a formal recommendation from the World Wide Web Consortium (W3C) similar to the language of today's Web pages, the Hypertext Markup Language (HTML).

X Session

When a user logs in to a computer and runs programs under the X protocol they create and X session.

X Terminal

A terminal specially designed to run an X server which allows users to display the output of programs running on another computer using the X protocol over a network.