git diff
比较 工作目录(Working tree)和 暂存区域快照(index)之间的差异

git add   
把修改加入暂存区域

git diff --cached 或 git diff --staged
查看暂存区和上次提交时的快照之间(HEAD)的差异


git diff HEAD
显示工作版本(Working tree)和HEAD的差别

git diff HEAD  --stat
note.txt | 3 +++
1 file changed, 3 insertions(+)
 
--stat  显示简单对比结果


git diff branch001
当前目录与另一分支对比


git diff HEAD^ HEAD
比较上次提交和上上次提交


git diff SHA1 SHA2
比较两个历史版本 


git diff branch1 branch2
比较2个分支内容