Ethereum is different from Bitcoin in many ways, but the most significant difference is that Ethereum is a programmable blockchain. This means that users can build applications and smart contracts on the Ethereum blockchain.
Bitcoin, on the other hand, is a digital currency. Bitcoin is used for payments and transfers, but it is not programmable.
For example, using the Ethereum blockchain, you can create a decentralized application (DApp) that allows users to buy and sell items using Ether (the native cryptocurrency of Ethereum). This DApp would be powered by smart contracts, which are pieces of code that execute when certain conditions are met.
On the other hand, using Bitcoin, you can only transfer and receive Bitcoin. There is no way to create a DApp or smart contracts.