I am new to Haskell and trying to learn it with learnyouahaskell.com and Pluralsight Haskell course. 

And i have a very noob question.

I understand that if .. else is just a syntactic sugar over case. But what about guards then ?

Are guards also case in different syntax ? Or vice versa ? Like with an example.

I can do the same thing with both of them. 

As i understand the only different thing is, with case i can manipulate the parameter (like here in the example i used removeOdd) and can use the manipulated parameter to decide what to do after that. 

So i will not need to use removeOdd function inside the case. ( maybe i will need to use in every guard definition if i choose to use guards )

Is this it? 

Is this the only difference between them ?

And if it is, why haskell needed do implement both of them. Can't we use function like removeOdd before using it on case or guard functions ?

Thanks, and sorry if my english is bad.

Semih Masat