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)

LOOK UP ANOTHER TERM


abstraction layer

Software that translates a high-level request into the low-level commands required to perform the operation. The most common abstraction layer is the programming interface (API) between an application and the operating system. High-level calls are made to the operating system, which executes the necessary instructions to perform the task.

The domain names and URLs on the Internet are another common abstraction layer, enabling an alphabetic name such as computerlanguage.com to be converted into the numeric IP address of the Web server (see Internet domain name).

Multiple Layers of Abstraction
Today's applications are often programmed in multiple layers of abstraction. For example, a program can be written by selecting menu options and dragging icons around the screen. These movements may be translated into a high-level language that is translated into a low-level language, which is translated into machine language. The farther away from the machine language of the computer that an operation is programmed, the more instructions are executed to perform the task.

Combine this with the interaction of the operating system, which itself may be executing 10 times as many instructions as necessary, and you understand why even on a fast computer, a user may be able to press the keyboard keys faster than the program can accept the input. Considering modern personal computers execute upwards of two billion instructions per second, compared to the first PCs that executed one million, the extra machine cycles are absorbed layer to layer, each one telling the next one what to do. See level of abstraction.



Personal Use Only

Before/After Your Search Term
BeforeAfter
absolute referenceabstraction level
absolute URLAC
absolute vectorAC '97
absolute zeroAC-1
abstract classAC-2
abstract data typeAC-3
abstract identifierAC adapter
abstract superclassac-standard router
Abstract Windowing ToolkitAC'97
abstractionAC1

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
Audio/VideoGraphics
MainframesSecurity
ProgrammingHealthcare IT
System design