Where is mantra found?

Excuse me, could you possibly enlighten me on something? I've been quite curious about this topic and I'm having a bit of difficulty finding the answer. Could you tell me, where exactly is mantra found? Is it something that's embedded in certain cultures or religions? Or is it more of a concept that's widespread and can be discovered in various forms and settings? I'd really appreciate it if you could shed some light on this matter for me.