TITLE: Definition of “maximal” and “minimal” 
QUESTION [5 upvotes]: Possible Duplicate:
difference between maximal element and greatest element 

When I first encountered the terms maximal and minimal, I confused them with maximum and minimum. Many of my classmates also got confused about these terms (although they did not realise it). One usually do not find good definition of these two terms in literature (especially in Engineering books).
How would you define these two terms such that any person reading about them would understand the difference between um and it's corresponding al (minimal/minimum and maximal/maximum) easily?  
P.S.: I may have got confused because English is not my native-tongue.

REPLY [3 votes]: The distinction is between partially ordered sets and totally ordered sets.
You can have several maximal elements of a partially ordered set because they are each greater than the elements they can be compared to individually, but they cannot be compared between them.
You cannot have more than one maximum element of a totally ordered set since all elements are comparable.