So, I'm following this thread: http://www.quiltingboard.com/t-82540-3.htm and wondering, Why are they discussing the pros & cons of starch vs sizing?

As a new quilter, I'm wondering if this is something I am supposed to be doing. Does it matter that I haven't on the quilts I've already made & given away?

My Quilting 101 class did not cover this at all. Can anyone help explain? Thanks!