Some more information about Linux permissions can be found on various pages on the web, for example this one
, covering both the textual and octal representation of permissions. The octal representation is a little more compact than the textual one, and not too difficult to understand, so you should get familiar with it. You'll be using octal representation also if (when) you set umask
, which you use to control default permissions when files are created. The difference is that with umask you're setting the mask, not the "direct" representation, so be careful.