What are altcoins, and how do they differ from Bitcoin?

Altcoins are all cryptocurrencies except Bitcoin. They emerged after its success to offer alternatives, improved features, or solutions to various problems. Unlike Bitcoin, which was created as a digital currency for storing and transferring funds, altcoins can have unique features such as enhanced security, anonymity, or faster transactions. Some altcoins, like Ethereum, also provide platforms for creating smart contracts and decentralized applications. The main distinction of altcoins is their variety of functions and goals they aim to achieve in the blockchain space.