I know that there are four editions of The Settlers of Catan so far. But how do you tell which edition it is when buying? Is it written somewhere on the box? The titles for the products in online shops sometimes contain the edition and sometimes don't, and I don't want to end up buying an old edition.
There are differences in cover art and publisher. And there are counting different languages, over 50 different editions of the base game...
The most common US versions are US third and US fourth editions by Mayfair... other countries' edition counts may vary, plus the US editions have made the rounds...
The current, US 4th Mayfair edition shows a scene with several colonists on a road along a wheat field, with a large sun in the background. The water is a puzzle frame.
The third is basically off-white front, with red sides, with a crest in the upper left, and an inset of some individuals negotiating in the lower right. The water is hexagonal tiles.
Some people's 3rd edition copies will have a 4th edition frame, rulebook, and port markers; these were provided in an "Adaptation Kit."
Both 3rd and 4th edition have 4 colors of pieces, and specific colors seem to have varied slightly, with red, blue, white and either yellow or orange; black and neutral wood were in the 5-6 player expansion.
The first and second are brown boxes with a sun in the upper left. The 2nd edition was essentially the same as the first, save for extra rules and different colors, and 1st edition may have been reprinted at the same time as second. 1st ed colors are red, blue, green, and natural wood; 2nd are black, purple, yellow, and orange, and the box might be stickered as 2nd edition. Note that some people will have combined a 1st edition and second edition for play with up to 8 players.
Mayfair used the same illustration for the Travel Edition as on 3rd, but the front is basically red. The pieces are much smaller, have large stubs, and the hexes have circular voids for the fixed numbers in the plastic board. The art and rules are pretty much the same as third, but all components are smaller.
There also was a Simply Fun version, retitled "Simply Catan", which shows a city against a large sun, and water in the front. It's a frame version, and has 3d plastic road, settlement and city pieces in red, orange, white and blue, with the board comprised of strips, rather than separate hexes. Further, the frame includes many rules elements.
And that's not counting the other games: The Card Game, the Dice Game, etc.
The BGG page has a photograph for for each version.
Your profile indicates that you are located in Russia. I only see one Russian language edition.
If you are looking at American Mayfair-published editions, the box art style is distinctively different between fourth edition and third edition, which are the versions I commonly see. The first and second editions have an identical box; the second edition has a sticker on the shrink and different color player pieces, but are otherwise the same.