Minor updates are those that changes only the last digit after the period (like from 1.5.035 to 1.5.036). Major updates are those that changes only the first digit after the period (like from 1.6.021 to 1.7.000). Upgrades are those that changes the digits before the period (like from 1.7.005 to 2.0.000).
We guaranteed that you will have free access to any minor update, of any product you purchased, for life. Bug fixing updates are always free. Major updates or Upgrades can be either free or with charge, depending on the situation.
Whatever the product version is called, we will charge you by the development time.