What is the difference between amend and squash commands? I tried both and found that both are doing the same for proper management.
In Git, commits are rarely actual destroyed, they just become orphans, or detached, meaning that they are not pointed to or reachable by a reference like a branch or tag.
"amending" and "squashing" are similar concepts though.
Typically, amending is a single commit operation in which you want to combine work that you have staged with your HEAD commit. This can be very convenient if you have just created a commit and realize that you need to add some content to it. Simply recall your commit command and use the --amend option.
Squashing is the more abstract term. I would say that an amend is a type of squash. Whenever you combine commits you could say that you are squashing them. If you have been working on a branch for a little while and have made 5 commits that taken together should be 1 commit, you can interactively rebase to squash them together.
There are several ways in Git to amend/squash, but they all center around the concept of organizing your commit history (which means re-writing the history of a branch) in this spirit of making it easier to grok.