What is Coinbase app?

What exactly is the Coinbase app, and what kind of functionalities does it offer? Could you please elaborate on its features and benefits for users interested in cryptocurrency? How secure is it when it comes to transactions and storing digital assets? Additionally, is the Coinbase app suitable for beginners who are just starting out in the crypto world, or is it more tailored for experienced investors? Lastly, how does it compare to other popular crypto platforms in terms of usability, fees, and overall reputation?