There are 3 attributes that are also called modes. Read, Write and eXecute.

To better understand where on earth does chmod 777 come from, I’m writing this simple post.

The 3 digits, 777 came from rwx, rwx, rwx which stands for the privileges of owner, group and others respectively.

Now, how come rwx is equivalent to 7?

It’s because r=4, w=2, x=1 (I suppose that’s the simplest way to put it).

So, if we are to do chmod 755, this means, rwxr-xr-x

and chmod 765 means rwxrw-r-x