Patch management is an area of systems management that involves acquiring, testing, and installing multiple patches (code changes) to an administered computer system.
Patch Management is mostly done by software companies as part of their internal efforts to fix problems with the different versions of software programs and also to help analyze existing software programs and detect any potential lack of security features or other upgrades.
Software patches help fix those problems that exist and are noticed only after the software's initial release. Patches mostly concern security while there are some patches that concern the specific functionality of programs as well.