Is the JavaScript Console (On Modern Browsers) There to Do Anything?

I've once opened it by accident, while playing Cookie Clicker a few years ago.

Now that I look back at it, I begin to wonder. Is there any purpose that the JavaScript console serves other than giving me infinite cookies in Cookie clicker?

Can I find security vulnerabilities/security flaws with it?

(I have a mini-website (owned by me) that I've been wanting to practice on). Will the JS Console help?

Does the JS Console do anything?