It is easily found in hypermarkets (before all in the format A4) or in stationery shops (A4 and A3). Display books have the same advantages that binder, including protection of your pages, possibility to modify easily the order of pages by changing the pocket pages and the reduced cost.
Here also, pay attention to the quality of transparent pockets (choose high quality and crystal).
Display books are probably a bit more aesthetic than the binders, as there is no ring, which is practical when you create a double-page, because the two pages face each other, almost touching each other.
The opening of a display book is often flexible, but you can find them also with rigid covers at a higher price.
A rigid cover is nevertheless preferable in order to facilitate the arrangement of your album and you can always enforce a flexible cover by adding a cardboard and then covering with tissue for a more beautiful aspect.
However, the weak point of a display book is to have fixed pockets with a definite number at the beginning (30, 40,60 pochettes), which does not necessarily correspond to the number of pages that you wish to create.
Thus, you may have too many protecting pockets or may lack some.
Another disadvantage: knowing that you work only on one side of the page, you will put two pages back to back in each protecting pocket; therefore, your album risks to become too thick, thus preventing the complete closing of the display book.
To partly resolve this problem, use backgrounds of thinner pages, avoid double or triple matting and releif embellishments.