Which chain is Uniswap on?

I'm curious to know which blockchain network Uniswap operates on. As a decentralized exchange, it's important to understand the underlying technology that powers it. Is Uniswap built on Ethereum, or is it hosted on a different blockchain platform? Clarifying this detail can help me better grasp the capabilities and limitations of the platform, as well as its potential for growth and scalability in the future.