OC - Optical Carrier
Representing the speed of fiber-optic networks. OC speeds can range anywhere between 1 and 48. Most hosting companies have OC3 connections, which allows for the transfer of data at a rate of up to 155.52 Mbps. Recently faster bandwidth connections are becoming available such as OC12, OC48, and OC192 with transfers of up to 9.6 Gb/S or the equivalent of 6,200 T1 lines.

Octet
An octet is one of the four numbers making up an IP address. Octets values can range from 0 to 255. Each octet can be expressed as 8 binary bits, hence the name octet. An octet can also be represented by 2 digits of Hexadecimal.

ODBC - Open Database Connectivity
A common standard of Microsoft that allows relational and non-relational database programs - like dBase, Oracle, Microsoft Access - to access the information independent of its file format.

Offline
The state of the computer when it is not connected to the network (i.e. it is not online).

Online
Tha state of a computer when it is connected to the network and communicate with other machines.

Open Source
Free to use and modify. Some software developers use this method to gain support, popularity, and find holes in their software.

Optimization
Process of changing your site to gain better search engine ranking.

Origin
The ancestor that is appended to an unqualified domain name to form a fully qualified domain name. Usually set to the zone name.

OS - Operating System
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.

OSI - Open System Interconnection
A network standard developed by ISO and CCITT. It describes the way in which protocols of different layers communicate. This enables machines of different vendors to communicate over the network.

Outlook & Outlook Express
Email programs developed by Microsoft Corp. Easy to use. Outlook is more full featured with some contact management and scheduling.

Owner
A zone owns itself and all descendant names that are not delegated. A server for a zone can respond authoritatively for any domain name owned by the zone.