The short answer
Collecting postcards has an official name: deltiology, from the Greek word deltion, meaning a small writing tablet or letter. Someone who collects postcards is a deltiologist. Most of the other terms collectors use are not Greek — they simply describe the card: divided back, view card, linen, white border, real photo. Learn those few words and the hobby's vocabulary is mostly yours.
Deltiology and deltiologists
Deltiology is the collecting and study of postcards, and it sits alongside philately (stamps) and cartophilia (picture postcards of places, more precisely). A deltiologist might collect everything, or focus on one town, one publisher, or one subject such as lighthouses or national parks. The word impresses at shows, but behind it the practice is simply what collectors have always done: keep the cards that mean something, organize them, and learn the story each one carries. Our how to start a postcard collection guide covers the practice from day one.
Divided back, undivided back
The most useful term in the hobby is the divided back: a card whose back is split by a vertical line, with the message on the left and the address on the right. Before that design was allowed (in the United States, from 1907), cards had an undivided back — the whole back was for the address, and senders squeezed messages onto the front. Spotting which one you hold is the fastest way to date a card. The anatomy of a postcard guide walks through every part in order.
View card, real photo, and the print eras
A view card is any postcard showing a place — a street, a park, a landmark — which is most of what this atlas holds. A real photo postcard (RPPC) is printed from an actual photograph, not drawn or lithographed, and collectors date them carefully because they were often made in small local batches. Print-era names — white border (1915–1930), linen (1930s–1940s), chrome (from the 1950s) — describe the look of the card and are a shortcut to its age; how to date a postcard explains the full sequence.
Backs, stamps, and postmarks
Collectors talk about a card's back almost as much as its picture: whether it is written on, whether the stamp is still in place, and whether the postmark (the postal cancellation) is readable. A card mailed from the place it shows, with its stamp and postmark intact, is the complete object — the reason the Postcrossing guide and the preservation guide both say the same thing: leave old stamps where they are.
What is a deltiologist?
A deltiologist is a postcard collector — the word comes from deltiology, the study and collecting of postcards. In practice it means anyone who keeps and organizes cards, from a shoebox of hometown views to a systematic collection.
Why is postcard collecting called deltiology?
Deltiology combines the Greek deltion (a small writing tablet or letter) with -logy (study of). The name was coined in the mid-20th century to give the growing hobby a formal label, and it has stuck.
What is a divided-back postcard?
A divided-back postcard has a vertical line on the back, with the message on the left and the address on the right. In the United States this layout became standard after 1907; earlier cards are called undivided-back.
What should I call the postcard I keep?
If it shows a place, call it a view card; if the scene is drawn or printed from a painting, a vintage-style vs vintage distinction explains the difference between a reproduction and a genuine old card. Either way, you are a deltiologist now.