For more on symlinks see 'man ln'. Applying permissions Applying permissions with chmod can be done in two ways, using numeric notation, or symbolic notation. The numeric notation is what most UNIX users use, as it is shorter and more powerful. I will start with symbolic notation for the sake of newbies. Symbolic notation uses 3 letters, or symbols to represent permissions.
Lets analyze above two commands.
Numeric notation tends to be more powerful, and faster. Using numerical notation is personally my preferance. Using numerical notation, a number represents each possible permission. So, to apply rwx for owner, you add all these together, and get 7, for owner perms that 7 would go in the hundreds place, so lets say you want to make 'blah' rwx by owner, and nothing for group or others. This would be a very stupid thing to do.