The Serial library is a little different from the other libraries that are a part of the standard Arduino distribution. First, the library is automatically included in our sketches along with the normal Arduino library without us needing to do anything. Second, an instance of the Serial library is already created for us in the background that, on the Arduino Uno, is called
Serial, and on the Arduino Mega might be
Serial3. So when we use one of the upcoming functions, it will be preceded by the instance name
Serial and a period to separate the library name from the procedural or function name. As an aside, you might have noticed by now that many of the different libraries have similar procedures, including ...