There are many different card backs, which can give hints as to what might be found on that card.
The forest will mostly provide wood and food, the river mostly food and pelts, and the mountains stone and pelts. At home, you can craft tools and gain access to more people, dreams, and ideas.
This information is also shown on the base camp board.
Humans add their strength and expertise to your group, but must be fed. Dreams offer a variety of different positive actions. Ideas allow you to craft helpful items, and are always placed on the workbench.
There are also cards with red backs. Red card backs are a warning that there is something dangerous on this card. However, other cards may have dangers as well.
Some card backs include an additional image, which gives a hint as to what actions may be available on the front. They still count as the same card type.
This river card with a mammoth on it is still a river card.