Kindly explain the term documantation in software engennring.

Kindly explain the term documantation in software engennring.

Software is developed for users according to their requirements. Documentation can be considered as user manual. Documentation of software means document should be developed and provided along with software. Purpose of documentation is to aid software engineers in development and users in usage of that software. But the most important use of documentation is when some change is required in future. If documentation is not available then incorporating change in software is like working from scratch. But if we have documentation, then software engineers can easily incorporate that change by little effort in cost effective manner.