What is BTC vs STC?

Can you please clarify the difference between BTC and STC for me? I understand that both are forms of cryptocurrency, but I'm not sure what sets them apart from each other. Is there a significant difference in their value, purpose, or functionality? Also, are they both widely accepted and used in the cryptocurrency community, or does one have a larger following than the other? I'd appreciate any information you can provide to help me better understand the distinction between BTC and STC.