Perfect (Glue) Binding
Perfect binding is a process of Glue stick binding, where groups of pages are bound collectively using adhesive. The adhesive material applied on the spine area then after the cover wrapped around the collection of the pages. After the glue has dried, it will go in process of finishing production.
Then after the process of binding its look have very clean and professional printing products. You can check the output figure in the placing of the image area.