Can someone help me out with how transcripts work?

So in my highschool, I’ve payed my counselor a fee and she will send out my ONLINE transcript to all schools I’m applying to. However, some schools require hard copy transcript. When do I send those out?
(I know that UCs, you send out a hard copy transcript after you’ve been admitted).

The schools should have the deadlines on their admissions websites. Email if it is not clear.

Alright. But in general, is the deadline the hard copy transcript? Or is it the online transcript that is sent out by my counselor?

It really varies by school. Most schools will accept an electronic transcript. A few require a physical copy. Most require recipt before formal acceptance. A few will allow you to report grades and then submit after acceptance or even wait until you have a final transcript.

At my son’s high school (in Texas), students applying to colleges would send in a “six semester” transcript with college applications; it covered all courses and grades through the end of junior year. That’s what you used for college applications. Then you had to send in a final transcript after high school graduation to confirm your senior year grades and that you actually graduated. If I recall, the six-semester transcript was sent electronically, and then we paid for the final transcript to get a paper copy (it was only a few dollars). But I believe the high school even sent the final transcript electronically to the college that my son attended.