Whats the difference between a lead and a strand?
Think about long hair in a braid, which would normally be a three-part braid. There are a lot of strands of hair, but they all follow one of three paths through the braid. My rings frequently have more than one strand in each path, or lead. If you look at the page that attempts to explain about leads, you will see that some of the more complex rings only have one strand in them.
