The following two reactions are very similar. The only difference is that one adds a carbonyl  to the bezene  ring and the other adds a  alkyl group. They share the same mechanism and similar reagents. Let's say we want to add a group R ( regardless a carbonyl  or not) to the benzene ring. We would use silver chloride and the halide with the R group.   There are more to talk about acylation . After the carbonyl  R group is added, the carbonyl  can be reduced and give a  alkyl product. There is one limit  in acylation ,  we cannot add a formyl  halide to the reagent.