Dot is Forth convention for "print" where a single . means print integer..S (pronounced "dot S" or "print S") is for strings.
Both expect input from the stack.
." Begins a literal string you want printed immediately.
.S is a word that prints the stack (not destructively) pronounced "print stack"
EMIT in Forth prints one ASCII character (which byte value comes from the stack).
You are free to redefine whatever you like --it's your own language! Most of the punctuation in Forth has conventional meanings that help (a little) reading comprehension.
DECIMAL
: STAR 42 EMIT ;
: STARS ( n -- )
0 DO STAR LOOP ;
Type5 STARS
***** ok