Basic data question

Hey, unknown human being, thanks for the patience. I appreciate it.

maybe there's a misunderstanding about sending the data as an ascii c-string. is there?

Yes. I think I dont understand how serial comunnication works

If I send up to 255 directly to serial that is 1 byte right?

but if I convert it to ascii before send, that would be 50 53 53, 3 bytes right?

So I was thinking of sending 2 bytes without ascii covertion......