what is the use of wrap mode in animation

Unity Engine
1

what is the use of wrap mode in animation

void start()
{
animation.wrapMode=WrapMode.Loop;
animation["Catch"].wrapMode=WrapMode.Once;
animation["Catch"].layer=1;
}
2

Step One, Google: Unity Wrapmode

Step Two, Learn: Scripting Reference, Wrapmode

3

documenation cofusing .If i got help it wold be more helpful form me thanks in advance