Single VS Double Quotes

Print 1: Hello my name is $fname
Print 2: Hello my name is Dylan

As you can see there is a difference between print 1 and print 2.
Print 1 uses single quotes and that is considered a literal print, and prints the var name, $fname, that is written the single quotes.
Print 2 uses double quotes and that interprets the var to be used in the string, as shown it prints Dylan, not the var name $fname.