What is the importance of Operation Sea Lion?

The major
importance of Operation Sea Lion is that it was never carried out.  This was a plan that never
actually happened.  

Operation Sea Lion was the name given to the planned
invasion of Britain by the Germans early in .  The Germans, having easily swept across Western
Europe, were planning to invade Britain as well.  The operation was not given a specific planned
date, but it is widely believed that it would have happened in the fall of 1940.

This operation was never carried out because the German air force was never able to
achieve air or naval superiority over the English Channel. Without this, the operation would
have been too dangerous as British airplanes and ships could have devastated the flotilla
bringing the invading soldiers.