Examples: Should we go now? No, not yet. I'd rather wait until later. (I'd rather not go now and, instead, I would prefer to go one hour from now, tonight, or tomorrow or next week, etc.) I'd like to go now, but Tom would rather wait until later. (Tom would rather not go now but he would prefer to go at a time in the future)

It means the present time is not right and it's necessary to delay something. You are waiting for a later time to arrive. The word until is often used when talking about time. For example, "I'll wait until the start of summer to start playing golf again." The next Summer Olympics won't be until 2016.

Thank you both of you. :)