How does a fork affect a cryptocurrency?

Could you elaborate on how a fork, specifically in the context of cryptocurrency, impacts the digital asset? I'm curious to understand the mechanics behind it and how it potentially alters the fundamental structure or operations of a given cryptocurrency. Does it introduce new features? Does it create a separate branch of the blockchain? How does it affect investors, miners, and the overall community surrounding the cryptocurrency? Are there potential risks or benefits associated with forks, and how do they typically manifest? I'd appreciate a concise yet comprehensive explanation of the impact a fork has on a cryptocurrency.