In computer programming, the definition of an object is very simple: it is an instance of a class. To learn more, first see this glossary's definitions for the following words, preferably in this order: struct, and then class (as related to objects), and then instance.

The term object can also be used a bit more generally to refer to virtual things that software interacts with. For example, a filesystem object is a collection of data. This thing (the object) can respond in various ways, depending on what input it is given (including the reference to what kind of response is desired).

[#oop]: object-oriented programming (“oop”)
Computer programming that involves using objects and, naturally, classes (as related to objects).
[#oddabbr]: ODD

optical disc drive.

[#ontrack]: Ontrack

Ontrack Data International created DDO software named Disk Manager. Ontrack Data International since been renamed to Ontrack Data Recovery and is now named Kroll Ontrack Inc. after being bought out by Kroll, noted by Wikipedia's page on Kroll Inc.: section called “Ontrack and electronic data recovery”. Wikipedia's page on Kroll Inc. (above the “Contents” section listing sections) that Kroll “was a subsidiary of Marsh & McLennan Companies until it was acquired by Altegrity, Inc. on August 3, 2010.”)

MS KB Q73198: Ontrack Disk Manager Support for MS-DOS Partitions

[#ocr]: OCR

The phrase “optical character recongition” refers to analyzing graphics to determine what written letters exist in the graphics. For a period of at least decades, this non-precise recongition was much easier for people than for computers.

[#optdscdv]: optical disc drive (“ODD”)

optical disc drive

CDs (compact discs), DVDs, BDs (Blu-ray Disc)

The abbreviation is similar to HDD, FDD, SSD.

[#otoh]: OTOH: On the other hand
An English phrase, indicating a change in focus, perhaps to an alternative of whatever subject/topic/idea was being focused on. This is a sort of reference to a person having two hands, with the implication being to focus on the left hand instead of the right hand, or vice versa. Therefore, using the phrase more than once in a brief time may be a bit perplexing, as the naturally arising question is which other metaphorical hand is being focused on (since most human beings, at the time of this writing, were born with just two hands).
[#opsys]: “operating system” (“OS”)

The operating system is the software which has the most direct control of the hardware. The precise functionality included in an “operating system” varies, as differnet operating systems may have different amounts of included software and, therefore, different amounts of functionality that is provided by the operating system. In general, an operating system is a software product. The term “product” is meant to communicate the idea of an organized bundle of software, which is released as a single produced package of software.

Functionality that is common to operating systems is the ability to directly communicate to hardware, manage memory, access disks and provide some easy methods for other programs to be able to access specific objects stored on the filesystem, and to start any other programs/processes needed. Modern operating systems also tend to provide networking support (including a functional TCP/IP stack), security implemented through a permissions system, and other functionality related to task management including multitasking and stopping programs. Examples of features used by modern memory management include support for “virtual memory” (by swapping data to a “secondary storage” device such as a hard drive), and the ability to reserve memory for use by a specific program (and to track which individual program(s) memory segments have been reserved for).

The full Debian system contains quite a bit of software (with the vast majority being optional add-ons), while NetBSD is highly portable in part because it contains far less functionality (which allows the operating system to be much smaller).

See: operating system.

[#oui]: Organizationally Unique Identifier (“OUI”)
[#ouitwofr]: OUI-24

This information has moved. See: OUI-24 for more details. The start of an EUI-48/MAC-48 address is an OUI-24.