Serial.print(b) with no format specified, prints b as a decimal number in an ASCII string. For example,int b = 79;Serial.print(b);prints the ASCII string "79".
Serial.print(b, BYTE) prints b as a single byte. For example,int b = 79;Serial.print(b, BYTE);returns the string "O", which is the ASCII character represented by the value 79. For more information see the ASCII table.