What will happen if tick function doesn't finish prossessing within delta time?

For example, if I put a lot of things in a tick function, and it cannot finish execution within delta time, what will happen? Will the execution stops wherever it was and start over, or it will finish the execution no matter how much time it takes, and then wait till next delta time begins and start over? Or any other way?

Thanks,

Wcl1993

The delta time is the amount of time passed since the last tick. The next tick’s delta time would be higher if the previous one took a lot of time to process.