A sealant is a hard wearing protective coat that goes on after polish, before wax. AG have only recently done a 'wax' in the true sense of the word. EGP requires bonding to the car, hence having to leave it to dry and bond to the car. Wax is a decorative thing that does have some protection.
http://www.autoglym.com/enGB/product-pr ... FH&Range=1