Wire binding is a popular commercial book binding method, and is known by a number of different names including twin loop wire, wire-
Comb binding (sometimes referred to as "cerlox or surelox binding") is one of many ways to bind pages together into a book. This method uses round plastic spines with 19 rings (for US Letter size) or 21 rings (for A4 size) and a hole puncher that makes rectangular holes. Comb binding is sometimes referred to as plastic comb binding or spiral comb binding.
Perfect binding is often used, and gives a result similar to paperback books. National Geographic is one example of this type. Paperback or soft cover books are also normally bound using perfect binding. They usually consist of various sections with a cover made from heavier paper, glued together at the spine with a strong glue. The sections are milled in the back and notches are applied into the spine to allow hot glue to penetrate into the spine of the book. The other three sides are then face trimmed. This is what allows the magazine or paperback book to be opened. Mass market paperbacks (pulp paperbacks) are small (16mo size), cheaply made with each sheet fully cut and glued at the spine; these are likely to fall apart or lose sheets after much handling or several years.