Ether is the token that runs the Ethereum network. It’s how anyone can pay for transactions on the Ethereum network and support its functionality.
Ether is often referred to as a “cryptocurrency,” but it is not meant to be a currency like Bitcoin. Its main function is to provide “fuel” for the computational resources needed to run decentralized apps on the Ethereum network. However, Ether can be bought and sold, just like oil. Its price fluctuates based on supply and demand.