Hi, Apollo 11 got back to the Earth the same way that ALL Apollo flights that went to the Moon did. The only exception being Apollo 13, but that is a whole different story. Be sure to check that one out, well worth the effort!
The rest of the Apollo crews got back to Earth by simply firing their rocket engine on the Command Service Module, thereby breaking away from the Moon's gravity and letting the Earths gravity, + the rockets thrust, bring them back to the earth. Once they were ready to commit to the landing, they re-fired their rocket engine and turned the CM around so that it was heading tail first. They then fired once more and then released the Service Module and were left with just the Command Module or capsule. This is the part of the rocket that splashed down into the ocean.
I hope this answers your question.
Take care
The rest of the Apollo crews got back to Earth by simply firing their rocket engine on the Command Service Module, thereby breaking away from the Moon's gravity and letting the Earths gravity, + the rockets thrust, bring them back to the earth. Once they were ready to commit to the landing, they re-fired their rocket engine and turned the CM around so that it was heading tail first. They then fired once more and then released the Service Module and were left with just the Command Module or capsule. This is the part of the rocket that splashed down into the ocean.
I hope this answers your question.
Take care