And to keep re-checking until the register bit/byte value indicates that the status is OK for your program to continue.

It's like if you're waiting at home for a delivery, and you keep going to the window to see if the postman is there yet.
The troubel with this, obviously, is that you can't really get on with anything much else while you're waiting.

The alternative is to have the postman interrupt you by, for example, ringing the doorbell.
This means, of course, that you have to be ready to drop whatever you're doing to answer the door reasonably quickly - before the postman just gives up and goes away.

These are very common and well-established techniques in embedded development - googling "polled", "polling", and "interrupt-driven" will lead you to plenty of information, examples, etc,...