IEnumerable vs List - What to Use? How do they work?

Question

I have some doubts over how Enumerators work, and LINQ. Consider these two simple selects:

List sel = (from animal in Animals 
                         


        

Answer 1

Nobody mentioned one crucial difference, ironically answered on a question closed as a duplicated of this.

IEnumerable is read-only and List is not.

See Practical difference between List and IEnumerable