The photography festival "Paris Photo" and the Ville de Paris have partnered to create an online visual glossary of photographic techniques. For example: albumen prints, ambrotypes, canotype, daguérrotype, silver gelatin prints and pigment inkjet prints. This is not only interesting for art collectors, but also for other art and photography enthusiasts in general. In addition, some old techniques are again popular, e.g. wetplate or collodium photography.
Here is the link: https://www.parisphoto.com/en/Glossary/