Does using OpenAI cost money?

I'm just curious, does using OpenAI cost money? I've heard a lot about it recently, and it seems like a really powerful tool for language processing and AI tasks. But I'm also on a tight budget, so I'm wondering if it's something I can afford. Could you please explain the pricing structure to me? Is it a subscription service, or do you pay per use? Are there any free options available for those who are just starting out? I'd really appreciate it if you could clarify this for me.