What are patches, hotfixes, and service packs?

A patch is a program that makes changes to software installed on a computer. Software companies issue patches to fix bugs in their programs, to address security problems, or to add functionality.

Hotfixes are Microsoft's version of patches. Microsoft bundles hotfixes into service packs for easier installation. To keep your computer secure, you should keep your operating system up to date with the latest security patches and service packs.

Other companies have also adopted Microsoft's nomenclature of hotfixes and service packs for updates to their own software. Sometimes, a hotfix refers to a patch that can be applied without restarting the system. This is particularly useful when the system provides a critical service, such as a web server.

Also see:

• In Windows, how can I tell which service packs are installed?
• For Mac OS or Mac OS X, how do I obtain and install system software updates?
• What are service packs for Windows, and where can I get them?
• For Windows, how can I get software updates and patches?
• How can I update my installation of Microsoft Office?