Wikipedia says
Antibody opsonization is the process by which a pathogen is marked for ingestion and eliminated by a phagocyte. Opsonization involves the binding of an opsonin, e.g., antibody, to an epitope on an antigen. After opsonin binds to the membrane, phagocytes are attracted to the pathogen.
But why is it necessary for pathogen to bind with opsonin? Can't phagocytes attracted towards pathogen without opsonization? Simply I want to know what is significance of opsonization?