Differentiating Concat / Minification / Uglification
Concatenation - appending all of the static files into single large file.
Minification - removing unnecessary whitespace and redundant / optional tokens like curly and semicolons, and can be reversed by using a 'linter'
Uglification - transforming the code into an 'unreadable' form, that is, renaming variables/functions to hide the original intent, mostly un-reversible.