Hitler would have liked to invade England, and had planned to do so.  Once his armies got on British soil, there would be little they could do to stop him from conquering the British Isles.  What could stop him though, was the Royal Navy - the world's largest at the time.

By invading Norway, Germany had lost ten destroyers, a significant number, and really did not have the ships to attempt a cross channel landing, so the plan was scraped in favor of bombing them into submission.

This too could have worked, if Hitler hadn't thrown a temper tantrum when British planes bombed Berlin.  He ordered the targets shifted from airfields factories and radar stations to British cities.  This gave the Royal Air Force time to recover, and the invasion of England never happened.

Operation Sea Lion never happened, and that is what is really important about it.  The London Blitz did not really have much of a lasting effect on the war, although you can argue that it actually helped to make Germany lose the war.

Sea Lion was the planned German invasion of England.  But for various reasons, it was never even attempted.

One reason for this is that Hitler believed England could be forced to surrender via air power.  So he decided to bomb England instead of invading.  At first, air attacks focused on destroying the RAF.  This would have left England terribly vulnerable.  But then Germany started the Blitz and bombed cities instead.  This was terrifying, but it allowed the RAF to survive, rebuild, and ultimately hurt the Germans very badly (and certainly ensure Germany could not invade).