The regex star and plus characters, why are they too similar?

I have learned about the star * and the plus + characters in the regular expression in the curriculum, and it seems like they are too similar after I experimented on them both for some time.
so I need a rule upon which I can say “I will use the star * character over the plus + character for this specific reason.”
I’m not gonna give examples because it will be hard to follow the threads here and it’s complicated.
so my question is:
is there anything I should know or we should know that can be confusing about these two characters and what they do? whatever you can add is useful. just give a comment.

the + means “one or more”, the * means “zero or more”, which one to use depends on the pattern you want to match, they are really similar