That’s correct, yes. You are allowed to use your free hosting for as long as you want, but it is required that you actually use it. Many people set up an account, decide it’s not what they are looking for, and forget about it. After all, why would they bother cleaning up after themselves? But that would leave millions of accounts on our servers that nobody cares about, but do take up server space, which we would rather give to people who actually do want to use our services.
The only requirement is that you get a few page views every month. Just having any traffic is sufficient, if you check your site yourself you’re already safe.
If you don’t have any traffic in a month, your account will be suspended, but you can reactivate your account yourself, until the account is fully deleted, which doesn’t happen for at least 20 days after suspension.
A hit is a hit. If you don’t know what it is, there is a Wikipedia article about it: Pageview - Wikipedia
a hit refers to a request for any file from a web server
If you want to more about the limit: