What is stMATIC?

Could you please clarify for me what exactly is meant by "stMATIC"? I'm not familiar with this term in the context of cryptocurrency or finance. Is it a specific type of token or cryptocurrency? Or is it a platform, service, or feature related to the MATIC blockchain or Polygon network? I'd appreciate any additional information or context you could provide to help me understand what stMATIC is and how it fits into the broader cryptocurrency and finance landscape.