Explanation of program needed

Using Arduino Programming Questions
8

[2.) if(nss.available() >= 3) - i don't understand how this works./quote]

2) check to see if at least three characters have been received from the nss serial interface

does one character refer to one byte?

  1. Not necessary for oxyLevel, and not necessary for most of heartRate.

I don't understand this quote..sorry.. :frowning: