Glossary of Terms
Apache is an open source Web server that is distributed free.
Apache runs on Unix-based operating systems (including Linux and
Solaris) and Windows 95/98/NT. Apache was originally based on
the NCSA server, but is now an independent product, supported by
the nonprofit Apache Software Foundation.
A browser is a software application that lets you access
information on the Internet. Browsers can read HTML and send
HTTP or FTP requests for services on the Internet. Browsers are
usually associated with the World Wide Web portion of the
CGI, or the common gateway interface, provides a standardized
method for Web servers to send a user request to an application
and to receive information back for the user. For example, when
you click on a URL link, the Web server sends the requested page
to you. CGI is part of the HTTP protocol. CGI works in many
different languages, and across several different platforms.
A client is a company or individual requesting services from an
Internet presence provider. A client is a customer of a Web
hosting company, or a user of Internet services. In hardware
terminology, a client is a computer system or a software package
that requests services or information from another application
that resides across the network. Think of the client as your PC
or workstation, through which you access programs and data
across a network or the Internet, usually on a server. In very
simple terms, a client is a user.
DB WebAdmin is a web-based administration tool that allows to
manage a whole MySQL server as well as a single database.
DNS, short for Domain Name System, is a distributed database
that maps names and IP addresses for computers using the
Internet. DNS is a standardized system that identifies domain
A domain is a virtual address on the Internet for any
organization or entity. Technically, a domain is a group of
networked computers (servers) that represent an organization and
provide network services. However, several domains could reside
on one server, in dedicated space provided by a Web hosting
service. To the Internet user, a domain appears as space on one
server, regardless of the implementation. Domains are identified
by their familiar Internet URL (uniform resource locator)
addresses. For example, www.sw-soft.com is the name of the
domain where SWsoft information resides on its servers.
Syntactically, a domain name is a string of names or words
separated by periods. For example, a domain name such as:
hello.house.neighborhood.com includes the names of:
the host: hello
the subdomain: house
the domain: neighborhood
the organization type: com
Some top-level domain names:
arpa: ARPAnet (a Defense Department communications system that
established the Internet)
com: Commercial, for-profit organizations and businesses
edu: Educational institutions
gov: Government organizations
int: International organizations
mil: U. S.-based military
net: Internet access providers
org: Non-profit organizations
aero: Air-transport industry
name: For registration by individuals
pro: Accountants, lawyers, physicians, and other professionals
two alphabetic characters: the country code top-level domains (ccTLDs),
such as, for instance .uk for United Kingdom.
FTP, or File Transfer Protocol, is a method used to transfer
files to (upload) and from (download) a remote server. You can
use the FTP command to:
Copy a file from the Internet to your PC
Move a file from your PC up to the Internet
Rename an existing file
Delete a file
Update an existing file with more recent data
A gateway is a combination of hardware and software allowing
dissimilar systems to communicate by filtering data through
standardized protocols. Think of a gateway as a translator that
allows your PC to talk with other computers on the network.
In a network, a host is usually a computer that stores software
applications and data that may be accessed or retrieved by other
users. But a host can be any addressable device on the network,
not just a computer. The host provides services to other
computers or users. An Internet Service Provider may also be
referred to as a Web hosting company.
HTML, or HyperText Markup Language, is a standardized language
for presenting information, graphics, and multimedia on the
World Wide Web. HTML consists of hundreds of codes, tags, and
symbols that define the type of information and how it should be
displayed in a browser. HTML is universally understood on a wide
variety of platforms.
HTTP, or HyperText Transfer Protocol, is a standard for sharing
World Wide Web files. HTTP lets you communicate across the
Internet by carrying messages from your browser to a server.
IMAP, or Internet Message Access Protocol, is a method for
receiving e-mail messages from other Internet users on your
local server. IMAP lets you see message headers before choosing
and viewing the entire text of mail messages. You can
selectively retrieve mail messages with IMAP. Compare IMAP to
the POP and SMTP mail protocols.
An IP address (Internet Protocol address) is an internal number
that identifies a host on the Internet or a network. IP numbers
are invisible to end users, replaced in your user interface by
the more familiar domain names and URLs.
IP address pool is the range of available IP addresses.
Mail autoresponders are automatic replies to email sent to a
particular mail name. Autoresponders can include both a text
message and attached files. This mail function is often used on
mail accounts for individuals who are away for a certain period
of time, or are unable to check their mail for any number of
Mail groups are used for sending e-mail to a group of people
through one address rather than to each individual address. Mail
groups save you time and effort in reaching several people at
once; you only have to create one e-mail message to the group,
rather than several identical messages to everyone.
Mailman is software to help manage email discussion lists, much
like Majordomo and SmartList. Unlike most similar products,
Mailman gives each mailing list a web page, and allows users to
subscribe, unsubscribe, etc. over the web. Even the list manager
can administer his or her list entirely from the web. Mailman
also integrates most things people want to do with mailing
lists, including archiving, mail-to-news gateways, integrated
bounce handling, spam prevention, email-based admin commands,
direct SMTP delivery (with fast bulk mailing), support for
virtual domains, and more. Mailman runs on most Un*x-like
systems, is compatible with most web servers and browsers, and
most SMTP servers.
Mail redirects are used to forward or redirect email from one
POP3 mailbox to another email address. By creating an email
redirect or alias, messages are sent to a different email box
without the sender needing to know the new address. Email can be
redirected to an address outside the domain.
SQL is a Structured Query Language that was created as a
standardized method of defining, manipulating, and searching
data in a database. It is currently the most commonly used
database language. My SQL is a fast, easy-to-use, multi-user SQL
database server in a standard client/server environment. MySQL
handles graphics as well as text. For more information, visit
A network is a system of interconnected computers and peripheral
devices (such as printers).
Data that is transported across the Internet is divided into
small, manageable units called packets. Data packets can be sent
more quickly and efficiently across a network than the full
stream of data in a message or file.
Perl is an interpreted high-level programming language. Perl is
very popular among System Administrators who use it for a vast
number of automation tasks. Many CGI programs are written in
PHP (originally meaning Personal Home Page) is a server-based
HTML embedded scripting language that runs on multiple
platforms, primarily on Linux servers. PHP accesses and
manipulates data in a MySQL database, and helps you create
dynamic Web pages. You write HTML and embed code in the HTML
that performs a specific function. The embedded code is the PHP
portion of the script, identified in the HTML by special start
and stop tags. A PHP file has an extension of .php or .php3 or
phtml. All PHP code is executed on a server, unlike a language
more information on PHP. PHP hosting accounts requires a PHP Compiler to be loaded on the server.
POP3, or Post Office Protocol Version 3, is a method used to
receive electronic mail across the Internet, accommodating
different mail software packages and systems. POP3 receives and
holds all your e-mail on a server. You can then download all
your messages when you connect to the mail server; you cannot
selectively retrieve messages. Compare POP to the IMAP mail
PostgreSQL is an open source database system, that began as an
enhancement to the POSTGRES research prototype DBMS. Where
POSTGRES used the PostQuel query language, PostgreSQL uses a
subset of SQL.
A directory is an organized collection of files and subdirectory
folders on a computer. A protected directory is one that cannot
be accessed by all public users; you must have access privileges
to read information in a protected directory.
Python is an interpreted high-level programming language. You
can write web-based applications in Python that will run many
times faster than traditional CGI and will have access to
advanced features such as ability to retain database connections
and other data between hits and access to Apache internals.
Qmail is a secure and highly reliable e-mail message handling
system. It replaces the sendmail daemon on Unix and Linux
systems. Qmail is fast and uses little memory. Users can create
their own mail lists, and system administration is minimal.
Qmail uses the Simple Mail Transfer Protocol (SMTP) for message
exchange with other systems.
Rebooting simply means restarting a computer. You should not
reboot a server that has users accessing it until you have
informed the users that the server must be shut down
temporarily. Sometimes, an emergency necessitates rebooting a
server immediately, but it is not a recommended practice.
Secure HTTP (S-HTTP or HTTPS) is an encryption method uses to
protect documents on the World Wide Web. An alternative to
S-HTTP is an SSL certificate (or Secure Socket Layer) that
secures an entire session, not just a document or a file. S-HTTP
supports several different message encryption formats, and works
with any communication between clients and servers.
There are several different ways to control access to a computer
or network, to protect proprietary data, and to maintain
privacy. Security measures can be defined at several different
levels (at the server level, on a directory, for an individual
file, etc.) for optimum protection.
A server is a computer system (a combination of hardware and
software) that runs programs, stores files, directs traffic, and
controls communications on a network or the Internet. Clients
(also called users or workstations) access a server for specific
information and services.
An IP address that can be used for hosting by several clients.
In Plesk, this term refers to a set of directories and files
that get copied into a newly created virtual host directory
structure at the time the virtual host is created. It may be
used to have a set of CGI scripts included with every account
created in Plesk. It is very useful if you are looking to have a
more informative, customized welcoming index.html page, and it
is also helpful if you have anything else that needs to be
included by default within the directories of the virtual host.
SMTP, or Simple Mail Transfer Protocol, is a standard for
transmitting mail messages across different computers on a
TCP/IP network. SMTP can only be used when both the mail sender
and receiver are ready. If the destination PC is not ready, a
'post office' must temporarily store the mail. In that case, a
post office protocol such as IMAP or POP is used to retrieve the
SSI stands for 'server-side includes', a type of HTML comment
that directs the webserver to dynamically generate data for the
Web page whenever information is requested. SSIs can also be
used to execute programs and insert the results; therefore they
represent a powerful tool for web developers.
SSL stands for Secure Socket Layer, and is a set of rules used
for exchanging information between two computer devices using a
public encryption system. SSL establishes secure communications
between servers and clients. SSL provides a safe and
authenticated method of handling e-commerce transactions. Only
authorized users can access and read an SSL-encrypted data
stream. An alternative to SSL is Secure HTTP (S-HTTP), used to
encrypt World Wide Web documents (rather than securing an entire
session, as does SSL).
An SSL certificate is an electronic key that encrypts
transmissions between two computers on a public network,
providing privacy and security to the session. Think of an SSL
certificate as an electronic ID card for an individual or a
computer service. An SSL certificate confirms that a message
that you receive actually did come from the person identified.
The certificate key is issued by a third party. SSL certificates
are used for secure e-commerce communications, protecting
information such as credit card numbers and personal data. You
can generate an SSL certificate with a utility such as SSLeay.
Then, submit it to a certificate authority such as GeoTrust, Inc
TCP stands for Transmission Control Protocol, and is the primary
data transport protocol on the Internet. TCP transmissions are
fast, reliable, and full-duplexed.
Transmission Control Protocol/Internet Protocol, commonly known
as TCP/IP, is a data transmission protocol that was developed by
ARPA, the Advanced Research Projects Agency. ARPA is the
founding organization of the Internet.
Telnet is a method of accessing another remote computer. You can
only access the other computer if you have permission to do so.
Telnet differs from other protocols that simply request
information from a host computer, because it actually logs you
on to the remote computer as a user.
Tomcat is a server solution based on the Java Platform that
supports the Servlet and JSP specifications. Managed by the
Apache Jakarta Project, it is developed in an open and
A URL is a Uniform Resource Locator used to identify an
organization or domain on the Internet. URLs are standardized
names that are typically found on the World Wide Web portion of
the Internet. URL addresses identify domains on the network.
Read about Domains for more detail.
Simply put, a user is a client. In hardware terminology, a
client is the PC that you use to access information from other
computers (usually servers) on the Internet or network.
WebMail is a Web based interface to Unix system mailboxes. It
allows a user to access and administer his IMAP/POP3 mailbox via
the world wide web.
A web user is a user account within Apache that is used to
define locations for personalized web pages with individual FTP
A workstation is a user or client that accesses information from
other computers (usually servers) on a network.