Start Updating security

Updating security

The patch usually consists of a firmware image in form of binary data, together with a supplier-provided special program that replaces the previous version with the new version; a motherboard BIOS update is an example of a common firmware patch.

In this case, the patches usually consist of textual differences between two source code files, called "diffs".

Service packs for Microsoft Windows NT and its successors and for many commercial software products adopt such automated strategies.

Some programs can update themselves via the Internet with very little or no intervention on the part of users.

Microsoft Windows NT and its successors (including Windows 2000, Windows XP, Windows Vista and Windows 7) use the "service pack" terminology.

Historically, software suppliers distributed patches on paper tape or on punched cards, expecting the recipient to cut out the indicated part of the original tape (or deck), and patch in (hence the name) the replacement segment. Then, after the invention of removable disk drives, patches came from the software developer via a disk or, later, CD-ROM via mail.

The maintenance of server software and of operating systems often takes place in this manner.

In situations where system administrators control a number of computers, this sort of automation helps to maintain consistency.

Because the word "patch" carries the connotation of a small fix, large fixes may use different nomenclature.