https://www.youtube.com/watch?v=IU2ByZ-V26Y&list=PLuHgQVnccGMA8iwZwrGyNXCGy2LAAsTXk ================================================================================ mkdir test git init gistory ================================================================================ ================================================================================ Open new terminal cd test vim f1.txt # Insert a There's no changes because "adding a file" is regardless of Git ================================================================================ git add f1.txt ================================================================================ vim f2.txt git add f2.txt ================================================================================ ================================================================================ cp f1.txt f3.txt git add f3.txt Point: even if the file name is different, if the contents of the file are the same, Git points to same object file (7898...) Advantage of it: - Suppose 10000 files, each one is 10GB - In index, there are 10000 number of file name, like f1.txt, f2.txt, f3.txt - But 10000 number of files point to same one object file like 7898... ================================================================================ If contents is same, object file name is same