Is THETA built on Ethereum?

Could you please clarify if THETA is indeed constructed on the Ethereum blockchain? I'm curious to understand the technological foundation of THETA and whether it leverages the capabilities and functionalities provided by the Ethereum platform. Could you elaborate on this aspect, and if not, could you explain the alternative technological foundation that THETA is built upon? I'm interested in understanding the specifics of its architecture and how it differs, if at all, from other cryptocurrencies. Thank you for your time and consideration.