Dear student ,
Esterification is the reaction between an alcohol and a carboxylic acid in presence of an acid H+,
while the reverse of the esterification is known as hydrolysis of ester in presence of either an acid or an alkali , and when an alkali is taken for the hydrolysis of ester the reaction is known as saponification .
RCOOR' + H2O RCOO- + R"OH
Regards