manage branch

1.  cultivate branch， doing commiting operation on branch what was called cultivateing branch;

2.  if we create many branches, can develop multiple functions in the case of each other without affecting

3. topic branch, achieve a single feature on the branches

4.the role of a stable branches is usually played by master

5. merge branch                       git merge

6. head           points to the latest submission of the pointer in the current branch

7. git log --graph  output the log in the form of a chart

8. git reset  retrospect history version

9. conflict delete one of  the two

10. git commit --amend  modify the previous submission

11. git rebase -i compressed history submission

12.