Hi Giby ,
The following documentation will help you
https://docs.mendix.com/refguide/commit-dialog
https://docs.mendix.com/refguide/merge-dialog
https://docs.mendix.com/refguide/version-control#1-introduction
https://docs.mendix.com/refguide/version-control-menu
Have a look at the Learning Path on the Mendix Academy on how to use Version Management.
https://academy.mendix.com/link/module/213/lecture/1654/4.1-Introduction
Hope this helps.