Use of "If Equal to"?

HI,
What's the use of If Equal to ?

1. I am unable to connect the 'failure' or 'success' output , if I try to it says cannot link input to input (which makes sense)
2. I want to do a calculation if Color='All Color' keep blank , if not keep the value inside , which I am able to do with "Validation - IS equal to" but whats' the use of if Equal to

 

This one works

Now that you posted it , it looks so logical ! Thank you !