What is Coinbase Exchange?

Could you please elaborate on Coinbase Exchange? I've heard it mentioned in the cryptocurrency world, but I'm not entirely familiar with its functionalities and operations. I'm curious to know what sets it apart from other cryptocurrency exchanges. Specifically, I'm interested in its security measures, the range of digital assets it supports, and any unique features or services it offers. Additionally, I'd like to understand the process of trading on Coinbase Exchange and how users can fund their accounts. Thank you for your time and assistance in clarifying this topic.