What is the difference between ETH and stETH?

I'm curious about the distinction between ETH and stETH. Could you explain the key differences between these two cryptocurrencies? ETH, as I understand, is the native token of the Ethereum blockchain, powering transactions and smart contracts. But what about stETH? Is it a derivative or a variant of ETH? And how does it differ in terms of functionality, usage, and even risk? I'm also interested in knowing how investors and traders might approach these two assets differently, given their unique characteristics. Could you elaborate on this, please? Thank you for your insights.