Web Hosting Terms and Definitions

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Address
Unique identifier of a web page. URL (Uniformed Resource Locator) is more frequently used for this purpose. Back to Top

Apache
Apache is an open-source (source code is freely available and can be shared) HTTP Web Hosting server software. According to Netcraft survey, it is currently the most popular web server on the Net. It is usually run on Unix operating system versions like Linux or BSD, but it can also be run on Windows. It is a full-featured server with many powerful add-ons freely available. Apache's major competitor is Microsoft's IIS. Back to Top

Archive
Archives are large files containing valuable data. Archives are often compressed to save space. Back to Top

ASP
Active Server Pages. ASP is Microsoft's server-side scripting technology. An Active Server Page has an .asp extension and it mixes HTML and scripting code that can be written in VBScript or JScript. ASP is distributed with Microsoft's IIS web server, so most host using IIS will also offer ASP for dynamic web programming. ASP.NET is the next version of ASP. Other popular server-side scripting languages are Perl, PHP, ColdFusion, TCL, Python, and JSP. Back to Top

Backbone
Main high-speed network connection composing the Internet. Backbones are operated by major telecommunications companies like Sprint, MCI, or AT&T. Internet backbone maps are here. Back to Top

Bandwidth
Bandwidth is the amount of data that can be transferred over the network in a fixed amount of time. On the Net, it is usually expressed in bits per second (bps) or in higher units like Mbps (millions of bits per second). 28.8 modem can deliver 28,800 bps, a T1 line is about 1.5 Mbps. Back to Top

Bot
An automated piece of software that can be used in chat rooms or to crawl the web. Back to Top

C/C++
Popular programming languages (C++ includes objects) that can be used to create server programs that run after compilation. C and C++ were not designed specifically for web programming, but they can still be useful, especially because mature compilers producing very fast code and large code libraries already exist. Back to Top

Cascading Style Sheets (CSS)
A style-sheet determines how the HTML document is displayed by the browser. The current version of CSS is version 2 (CSS2). Back to Top

Certificate
Digital ID used for SSL transactions. It includes owner's public key, the name of the owner, the issuer, hostname, and the expiration date. Back to Top

CGI
Common Gateway Interface. A standard for interfacing web servers with an executable application. A CGI program can be written in any language like Perl or C/C++ and it is often stored in a special directory like /cgi-bin. CGI is often used to process data from HTML forms. Back to Top

cgi-bin
A directory on the server where the executable CGI scripts reside. Back to Top

clustering
Connecting many computers and making them appear as one machine. This is done to increase reliability and performance. Back to Top

Co-location
Putting a web server in a dedicated facility that provides high-speed Internet connection, security, environment, backup power, and technical support. Unlike the dedicated server, the client controls both hardware and software. Back to Top

Cobalt RaQ
Server appliance made by Cobalt specifically for hosting companies. Newest RaQs are Linux-based and provide an easy-to-use interface. RaQs have no features that can't be had in a regular Linux box but they offer pre-installed programs and Cobalt's support. Here is the discussion forum for RaQs. Back to Top

ColdFusion
ColdFusion is an easy to use server-side scripting language developed by Allaire. It comes with ColdFusion Studio, a visual IDE. Here is Allaire's ColdFusion page. Other popular server-side scripting languages are ASP. Perl, PHP, TCL, Python, and JSP. Back to Top

Control Panel
Control panel included in web hosting packages is an online web-based application that allows you to easily manage different aspects of your account. Most control panels will let you upload files, add email accounts, change contact information, set up shopping carts or databases, view usage statistics, etc. Back to Top

CPU
Central Processing Unit. The most important part of the computer. Back to Top

Data transfer
In Web hosting, the total size of files transferred by an account in a month. Sites with a lots of graphics, downloads, or streaming audio or video and a lot of visitors will require plans with more available transfer. Back to Top

Database
Data in a structured format stored on a web server. Most popular type is a relational database. The most common query (information retrieval) language for relational databases is SQL. Linux-based hosts most commonly include MySQL database and Windows NT-based hosts usually include Access or MS SQL databases. Back to Top

Dedicated Server
Similar to co-location, except that you lease or rent hardware from a Web host. The main advantage over co-location is easier upgrade and usually better support. Getting a dedicated server or co-locating is necessary for sites that outgrow shared servers because they use a lot of bandwidth and resources or they require total control over software environment. Back to Top

DNS
Domain Name System. Internet service that maps Internet domains into corresponding IP addresses. DNS database is distributed and replicated among many DNS servers, so when you change your domain's IP address, the changes take a while to propagate. Back to Top

Domain name
Domain name is an easy-to-remember address that can be translated by DNS into server's IP address. Domain names are hierarchical. Domain's suffix indicates which TLD (top level domain) it belongs to, for example .com, .gov, .org, .net, or .jp. Recently ICANN (Internet Corporation for Assigned Names and Numbers) added several new TLDs, like .biz, .pro., and .museum. Back to Top

Firewall
Firewall refers to either software-only or separate software and hardware combination that serves to protect an internal network or a computer from attacks and unauthorized access by sitting between the Internet and the internal network. Back to Top

FrontPage Extensions
Microsoft's server-side applications that lets users of FrontPage Web site creation tool to incorporate "web-bots" that perform pre-packaged function like full-text Web site searching or adding a hit counter. FrontPage extensions are also available for Unix-based operating systems but some hosts refuse to use them because of potential security holes. Back to Top

FTP
File Transfer Protocol. The Internet protocol defining how to download and upload files between a client and an FTP server. Popular client FTP programs are CuteFTP and WS_FTP. Major browser also have FTP capability. Back to Top

GIF
(Graphics Interchange Format) A graphic file format invented by Compuserve. One of the most widely used formats for internet and web. Uses a lossless compression method, thus ensuring that the quality of the image is not lowered. Back to Top

Gigabyte
1024 Megabytes. Back to Top

Hit
In the WWW world "hit" is used to describe a single request made by a web browser. The data transmitted by the web server in response to the request is a text file or a binary file (images, audio, video, executables and other data). Back to Top

Home Page
Main web page owned by a company, organization or an individual. This is the page that is initially displayed when user makes a request for a particular domain name. Back to Top

Host
A networked computer dedicated to providing a certain kind of service. Usually refers to a computer that stores the website files and has a web server running on it. Back to Top

HTML
(Hypertext Markup Language). It is the language in which web pages are written. It allows the images to be combined with text and offers wide range of formatting capabilities. One of the most important features of HTML is hypertext, that allows web pages to be liked one to each other. HTML relies on tags, which have the following form: Hyperlink
A part of the web page that links to another web page. By clicking on a hyperlink user redirects the browser to another page. The word hyperlink is sometimes shortened to just "link". Back to Top

Image Map
An image displayed on the webpage that has different areas that are hyperlinks. By clicking on different parts of the image browser can be redirected to another webpage, or can display modified version of the current one. Back to Top

IMAP
Internet Message Access Protocol. A method allowing a client email program to access remote messages stored on a mail server. The protocol includes operations for creating, deleting, and renaming mailboxes, checking for new messages, message parsing, searching, and setting and clearing flags. IMAP was originally developed in 1986 at Stanford. Back to Top

InterNIC
The organization that handles domain name registrations. See http://www.internic.net/ Back to Top

Intranet
A part of an organization's network that is private. Only authorized individuals have access to the intranet. Besides that an intranet is very similar to the Internet in a sense that it offers the same services and uses the same protocols. Back to Top

IP
(Internet Protocol) is tha main protocol used on the Internet. Back to Top

IP Address
Internet Protocol Address. A unique number identifying all devices connected to the Internet. This number is usually shown in groups of numbers from 0 to 255, separated by periods, for example 207.46.230.218. Back to Top

Java
Sun's popular programming language. Java is a platform-independent (at least in theory), crash-protected, object-oriented language that can be used to write applets that run in a browser, servlets that run server-side, or independent programs. Java's syntax is similar to that of C++. Back to Top

JavaScript
Simple, client-side programming language created by Sun and Netscape. JavaScript can be embedded in HTML pages to create interactive effects and do tasks like validate form data. JavaScript is a separate language from Java. All popular modern browsers support JavaScript. A few hosts support server-side JavaScript. Back to Top

JPEG
(Joint Photographic Experts Group) A image compression format designed for the Internet. Uses lossy compression, meaning that the quality of the image can be lowered. Back to Top

JSP
Java Server Pages. Extension of Java Servlet technology for combining Java server-side programs and HTML. JSP pages have an extension .jsp. Back to Top

Kbps
Kilobits per second. 1Kbps = 1024bps. Back to Top

Kilobyte
1024 bytes. Back to Top

LAN
Local Area Network. A network of devices (computers, printers, hubs) occupying a small area. Usually LANs do not span more than one building. LANs are very fast compared to WANs. Back to Top

Linux
A free UNIX-like operating system developed by Linus Torvalds. Linux and FreeBSD are very often used by hosting companies as their operating systems. Back to Top

MBps
MegaBytes (MB) per second, 1 MB = 1,048,576 bytes Back to Top

Mbps
Megabits (Mb) per second, 1Mb = 1,048,576 bits Back to Top

Megabyte
1MB = 1024 KiloBytes = 1,048,576 bytes Back to Top

MHz
MegaHertz = 1.000.000 Hertz Back to Top

MPEG
(Motion Picture Experts Group) video compression format for movies or animations. Back to Top

MySQL
Most popular open-source relational database. Many Unix-based plans allow MySQL databases. Back to Top

Operating system
A software heart of the computer. It is a set of programs that manage the hardware resources of a computer, provide the environment for application programs to run and provide the user interface. Most known operating systems are: different flavors of Unix (SunOs, HP-UX, Irix, FreeBSD, Linux,...), MacOS and Windows. Back to Top

Perl
Open source CGI scripting programming language. Written in 1987. Still one of the most popular web programming languages mostly due to its powerful text-manipulation facilities. A huge number of Perl scripts are available for download. Back to Top

PHP
PHP is an free, open-source server-side scripting language. PHP code can be embedded in HTML. PHP files usually have extensions like .php or .php3. PHP language style is similar to C and Java. Here is the PHP group web site. Other popular server-side scripting languages are ASP, Perl, ColdFusion, TCL, Python, and JSP. Back to Top

POP
Post Office Protocol. Popular but inflexible email retrieval standard. All messages are downloaded at the name time and can only be manipulated on a client machine. Current version is POP3. Back to Top

Port
A socket on the computer or other network device used to connect it to the network. Back to Top

RAID
Redundant Array of Independent (or Inexpensive) Disks. Type of disk, often used on servers, where several physical disks are combined into an array for better speed and fault tolerance.
Level 0 implements data striping where file blocks are written to separate drives. Does not provide fault tolerance, because failure of one drive will result in data loss.
Level 1 implements data mirroring. Data is duplicated on two drives either through software or hardware. Provides faster read performance than a single drive.
Level 2 - not used in practice. Data is split at bit level at written to multiple drives.
Level 3 - requires at least 3 drives. Data block is striped at byte level across drives and error correction codes (parity info) is recorder on another drive. Provides fault tolerance but slower writing performance.
Level 4 - Similar to Level 3 but provides faster performance because it uses blocks for striping.
Level 5 - Similar to Level 4 but improves performance but also striping parity info across multiple drives.
Level 6 - Similar to Level 5 but also uses second parity scheme for better fault tolerance.
Level 7 - Proprietary RAID design by Storage Computer Corporation. Faster than other levels because it uses multiple levels of cache and asynchronous I/O transfers.
In addition multiple RAID levels can be combined to improve performance or reliability. Back to Top

Raw Logs
Raw access data updated in real-time that can be downloaded and used by any statistics program. Typically each line show the user's IP, date and time of the access, what kind of request was done, which document was requested, HTTP status code, bytes transferred, referrer, and user agent info. If a host doesn't have statistics, you'll need access to raw logs to identify who your site's visitors are. Analyzing raw logs can also provide more detailed look at site accesses than stats. Back to Top

Server
A networked computer that handles client requests for Web pages. Back to Top

Setup fee
Initial fee charged by a host to set up your hosting account. Back to Top

Shopping Cart
Software that allows users to select products from a Web catalog, modify their choices, calculate prices, review their choices, and order them. Many hosts with e-commerce plans offer installed shopping carts, but you can always get a shopping cart of your choice instead. Back to Top

SQL
Structured Query Language. Limited programming language used for updating and performing queries on relational databases. All databases share a common subset of SQL. Most popular SQL databases available with hosting plans are MySQL and MS SQL. Back to Top

SSH
Secure Shell. Developed by SSH Communications Security, it is a standard for encrypted terminal Internet connections. SSH programs provide strong authentication and encrypted communications, replacing less secure access methods like telnet. Back to Top

SSI
Server-Side Includes. Instructs the server to include some dynamic information in a Web page before it is sent to a client. This dynamic information could be current date, an opinion poll, etc. Many hosts require that SSI pages have .shtml extension to reduce the load on servers by not having to parse non-SSI pages. Back to Top

SSL
Secure Sockets Layer. Protocol developed by Netscape to provide encryption for commercial transactions data that should be protected while traveling over the Internet, like credit card numbers. SSL uses https protocol. Before using SSL in commerce, you'll also need to get is a certificate from a Certificate Authority. Back to Top

Static IP
If a host offers a static IP, it means that your site will be assigned a unique and unchanging IP address. See the FAQ for some possible advantages of using a static IP. Back to Top

T1
Dedicated telecommunications line providing 1.5 Mbps of bandwidth. Consists of 24 individual channels 64 Kbps each, that can be configured for voice or data transmission. T1 lines can be leased by businesses that required a dedicated Net connection of with higher reliability than a DSL and faster than an ISDN line but are still quite expensive. Back to Top

T3
Dedicated telecommunications line providing 44 Mbps of bandwidth. T3 lines are often used by ISPs to connect to the Internet backbone. Back to Top

TCP/IP
(Transmission Control Protocol/Internet Protocol). This protocol suite is the de facto standard for the today's Internet. TCP is a higher level protocol that runs on top of the IP protocol. Back to Top

Telnet
Character-based protocol for connecting with remote systems. Still popular among hosts, but it is being replaced by much more secure SSH access. Back to Top

Terabyte
1024 gigabytes Back to Top

Unix
A family of multi-user operating systems, first developed by AT&T Bell Laboratories in the 1970s and then licensed to many universities. A basis for Linux, a very popular operating system among web hosts. Back to Top

UPS
Uninterruptible Power Supply. UPS keeps the server running on a battery for several minutes after a power outage, allowing for a clean shutdown without loss of data. UPS can also shield the server from line voltage spikes and drops. Back to Top

URL
(Uniform Resource Locator) is a way of addressing used for world wide web. An URL consist of the type of service (protocol), then the host name and then the file on the host. Back to Top

WAV
An audio file format. Very accurate, but offers no compression, thus resulting in very large files.Back to Top

ZIP
A popular compression utility. Back to Top