Alkalinity: It's the capacity for water to neutralize acids. This is also known as its buffering capacity – its ability to maintain pH levels and resist changes upon addition of an acid or base.
pOH Scale: A measure that quantifies the basicity or alkalinity; it’s analogous but opposite to pH because it measures OH- ion concentrations instead.
Hydroxide Ion Concentration: The number hydroxide ions (OH-) per unit volume; this is directly related with pOH and base strength.