https://www.youtube.com/watch?v=ZrJHsk73y84&list=PLuHgQVnccGMA8iwZwrGyNXCGy2LAAsTXk ================================================================================ git status git commit commit message is 1 ================================================================================ git log ================================================================================ ================================================================================ After commit, above object file is created You can see linked object file named e42e.... ================================================================================ See that e42e.... file ================================================================================ vim f2.txt git add f2.txt ================================================================================ object file after add ================================================================================ git commit object file after commit see and click the parent you can see the previous commit See that "2 tree values" are different ================================================================================ Click tree of "first commit" ================================================================================ you can see the "z" in f2.txt ================================================================================ click tree of "second commit object file" it has y z in f2.txt ================================================================================ mkdir d1 cp f1.txt d1/f1.txt git status ================================================================================ git add d1/f1.txt git commit ================================================================================ ================================================================================ blob object file contains "contents of the files" tree object file contains "information of blob" in tree structure commit object file contains "information of commit"