What does 3 cores mean?

Could you please clarify for me what exactly is meant by the term "3 cores" in the context of computer hardware or possibly in relation to cryptocurrencies and finance? I'm not entirely familiar with the specific terminology and would appreciate a concise explanation. Could you also provide any examples or scenarios where this concept might be relevant? It would be helpful to have a basic understanding of how it fits into the broader field of cryptocurrency and finance. Thank you for your assistance in clarifying this matter.