Difference between !word and !*mask*

Cyberwebby

Hello,
Can someone please explain the difference between !word and !*mask*? I have asked this question in another thread and just can't seem to an answer. Not sure if there's some type of language barrier or what.

Sven

class << means this has to be present by itself but will not match e.g. classwork

*class* << means it will allow anything even classword as * stands for any or none char in front or back