How does the Kraken work?

Could you elaborate on the functionality of Kraken? I'm particularly curious about how it operates as a cryptocurrency exchange platform. Does it offer a user-friendly interface for buying and selling digital assets? Are there any unique features that set Kraken apart from other exchanges in the market? Additionally, what kind of security measures does it implement to protect its users' funds and personal information? Lastly, can you shed some light on the fees associated with trading on Kraken, and how they compare to other exchanges?