what is the difference between a galvanized cell and an alkaline dry cell?

Galvanic cells are classified as either primary or secondary. A primary cell is used once and then thrown away when exhausted. A common example is an alkaline dry cell. 

Alkaline cells are a subset of galvanic cells. Galvanic cells are more generic and use any metals. Alkaline batteries are a type of disposable battery or rechargeable battery dependent upon the reaction between zinc and manganese (IV) oxide (Zn/MnO2). The alkaline battery gets its name because it has an alkaline electrolyte of potassium hydroxide, as opposed to the acidic electrolyte of the zinc-carbon batteries which are offered in the same nominal voltages and physical size.