What is the meaning of ring bearer?

Excuse me, could you possibly explain what the phrase "ring bearer" actually signifies? I've encountered it in a few contexts, but I'm still a bit hazy on its precise definition. Is it related to some sort of ceremony or event? Could you perhaps provide a more detailed explanation or some examples of its usage? I'd really appreciate it if you could clarify this matter for me. Thank you in advance for your assistance.