how to use IEnumerable az an interface?

Hi everyone
I'm confused about IEnumerable. i don't know which it what's mean? and when can i use it as an interface?
I've faced with IEnumerable like this:

var sorted=
from value in values
orderby value
select value;

Diplay(sorted, "sorted:");

Public Static Void Display(IEnumerable result, string header)
{
cosol.writeline ("{0}", header);
Foreach (var element in result)
cosole.write("{0}", element)
}