Best practice to keep the changes in the project well documented

Question

What is the best practice and software you use to document change related document.

lso, how you prefer to document the changes in the project.

Let say, you got a requirement to make some changes in the project. How do you proceed?

• Do you take the complete backup before processing. Will this backup be documented. If yes, then how?
• How the change will be documented? Any template? How this will be shared between the peers?
• What will be the content of the change request procedure?
• Do you keep the affected code, queries etc in some folder/document?