Reaction between benzaldehyde and acetophenone in presence of dilute $NaOH$ is known as:

Benzaldehyde ($C_6{H}_{5}CHO$) has no $\alpha$ -hydrogen, while acetophenone ($C_6{H}_{5}COC{H}_3$) has $\alpha$ -hydrogens. The reaction between two different carbonyl compounds where at least one has an $\alpha$ -hydrogen in the presence of base is called Cross Aldol condensation (specifically Claisen-Schmidt reaction).