Tongs are used to handle the stamps so oils from your fingers do not get transferred to the stamps. They are also used to help prevent folds and creases to the stamps. The stamps are held in horizontal strips. The pages are divided by glassine paper to help prevent damage to the stamps. There are thousands of stamps issued each year.
Catalogs can be very big.
The Scott Standard Postage Stamp Catalog covers the entire world in six volumes. Many public libraries have copies of this catalog in their collection. So you do not have to buy these books. The catalog lists each stamp issued by a country, it assigns a standard number to the stamp, it gives a description of the stamp, and it provides an estimated value. The standard catalog number is important to the collector.