Alan Freedman -- The Computer Language Company - Computer Desktop Encyclopedia
Computer Desktop Encyclopedia
Longest-Running Tech Reference on the Planet

A CDE Definition

You'll love The Computer Desktop Encyclopedia (CDE) for Tech Term of the Day (TTOD)


Open System Interconnection

See OSI.


(1) (Open System Interconnection) An ISO standard for worldwide communications that defines a framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.

Never Completely Defined
At one time, most vendors agreed to support OSI in one form or another, but OSI was too loosely defined and proprietary standards were too entrenched. Except for the OSI-compliant X.400 and X.500 email and directory standards, which are widely used, what was once thought to become the universal communications standard now serves as the teaching model for all other protocols.

A Reference Model
The OSI serves as a reference model for all network protocols because its functionality exists in all communications systems, although two or three OSI layers may be incorporated into one. For details of the layers, see OSI model. For comparisons between the OSI model and other protocol stacks, see TCP/IP, NetWare, ATM, SNA and SS7.

(2) (Open Source Initiative) A non-profit corporation dedicated to promoting open source software. The OSI logo on software certifies that it is distributed under one of several approved licenses. For more information, visit See open source.

An Approved License
This logo can be used if software is distributed under one of several licenses approved by the Open Source Initiative.

Personal Use Only

Before/After Your Search Term
open source softwareopen systems
open source telephonyOpen Transport
open source Unixopen Web
open sourcedOpen webOS
open sourced softwareOpen With
Open StackOpen XML
open standardOpenAI
open standardsOpenAir
open storageOpenAL
open systemOpenBSD

Terms By Topic
Click any of the following categories for a list of fundamental terms.
Computer Words You Gotta KnowSystem design
Job categoriesUnix/Linux
Interesting stuffPersonal computers
InternetIndustrial Automation/Process Control
Communications & networkingAssociations/Standards organizations
HistoryDesktop publishing
ProgrammingHealthcare IT
System design