What does gimme a bit mean?

Could you please clarify what the phrase 'gimme a bit' means? Is it a colloquial expression used in a specific context, or does it have a more universal meaning? I'm curious about its origins and how it's typically used in conversation. Could you provide some examples of how someone might use this phrase in a sentence or conversation? Additionally, is there a difference in meaning depending on the tone or context in which it's used?