What problem does Uniswap solve?

So, I'm curious to understand the problem that Uniswap aims to solve in the world of cryptocurrency and decentralized finance. Could you elaborate on what gap in the market Uniswap fills, and how it differs from other decentralized exchanges that are currently available? Are there any specific challenges that Uniswap addresses that other platforms haven't been able to tackle effectively? Additionally, how does Uniswap's solution contribute to the overall growth and adoption of decentralized finance?