The word "camber" is just a word, it means a slight convexity in a surface. So without context it's just wild guesses...
If you're talking about hand planes, it's a convex curve applied to the normally straight blade, in the plane of the blade. It can be achieved by grinding the blade into an arc. Image from toolsforworkingwood.com:
One of the reasons to do it is to eliminate ridges formed at the sides of the plane when planing large surfaces and/or make cutting easier. Whether it's something you really want to do or not seems to be a topic of debate, so I guess it comes down to personal preference.
There is a good article about it here and a nice video here.
Sometimes a good way to find better search results for ambigious topics is to include the general field you're looking for with the word. For example, "camber woodworking".
If you're not talking about hand planes then you need to provide more context. If you're talking about tables perhaps it meant angles on the legs or something. If you're talking about cars visit https://mechanics.stackexchange.com/.