Halley's comet revolution period around the sun is 76 years so it comes again and again but shoemaker levy collided with Jupiter in 1994 so, it will never come in the space again.
Halley's comet is also known as comet Halley and it is the only short period comet visible from earth every 75-76 years. Halley is the only known short period comet that is visible to us with our naked eyes.
Shoemaker levy was a comet that collided with Jupiter in 1994 and perished upon the impact. It provided us the first sight of extraterrestrial collision in the solar system.