Here are few differences bewteen use and require which may make it more clear for you.

• use only expects a bareword, require can take a bareword or an expression
• use is evaluated at compile-time, require at run-time
• use implicitly calls the import method of the module being loaded, require does not
• use excepts arguments in addition to the bareword (to be passed to import), require does not
• use does not behave like a function (i.e can't be called with parens, can't be used in an expression, etc), whereas require does