A baseline is a line that is a base for measurement or for construction. The word baseline may refer to: Baseline (configuration management), the process of managing change in software or other fields. Baseline (sea), the starting point for delimiting a coastal state's maritime zones. Baselines of the Chinese territorial sea. Baselines of Indonesia. Baselines of the Philippines. Baseline, in underwater diving, a value used to convert cylinder pressure of a tank to free gas volume.
https://en.wikipedia.org/wiki/Baseline