What is the definitions of a condensation reaction?
The reaction of two molecules to give the desired product along with a smaller molecule.
Esterification is the classic condensation reaction:
A smaller molecule, water, is spat out of the reaction, and, usually, the water molecule can be removed from the equilibrium, and the equilibrium driven to completion to give the reasonably pure ester,
Other small molecules that could be condensation products include methanol, or hydrogen halide, or ethanol.