parseInt() returns the first valid (long) integer number from the current position. Initial characters that are not integers (or the minus sign) are skipped. parseInt() is terminated by the first character that is not a digit.
This function is part of the Stream class, and is called by any class that inherits from it (Wire, Serial, etc). See the Stream class main page for more information.
stream : an instance of a class that inherits from Stream.
list : the stream to check for ints (char)