Bags are sections of material or fabrics that are utilized to carry objects. Bags can be any variety of sizes, colors and shapes.
About Suitcases:
Suitcases are separate pieces of luggage that are used to contain items for use in travel. Suitcases often have wheels on the bottom of the bag to ease in the movement of the piece.
About Zipper:
A zipper, sometimes called a 'slide fastener' is a device consisting of two toothed tracks or spiral metal or plastic coils, each bordering one of two edges to be joined, and a piece that either interlocks or separates them when pulled.