In this reaction, chlorobenzene reacts with bromine (Br₂) in the presence of AlBr₃ (an anhydrous catalyst), leading to the substitution of one hydrogen atom of the benzene ring with a bromine atom. This is a classic example of an electrophilic substitution reaction, where the bromine acts as the electrophile and the reaction occurs at the para position of the benzene ring. The role of AlBr₃ is to activate the bromine molecule, facilitating the substitution.
Thus, the correct answer is:
\[
\text{Electrophilic substitution reaction.}
\]