Chemical Anchors involve an epoxy resin or modified grout being injected in a hole predrilled to depth and cleaned of dust, a threaded stud is then inserted. Nuts can be tightened to the stud after a set time has lapsed.
Mechanical Anchors come in two types, expanding and under cut, they can be rapidly installed in a predrilled hold and are ready for immediate use, under cut anchors provide the higher holding power out of the two.