The styles
There about as many styles of camera cases as there are cameras, but most fall into a few broad categories. Fitted cases are shaped like your camera, and are generally made of leather, but can be just about any material. A fitted case is really more like a skin for your camera, and because each case is molded in the same shape as the camera, they're specific to each model. Some have flaps that can be opened to reveal the lens and/or back of the camera, while still staying attached to the camera body.

In my opinion, these fitted cases serve about as much purpose as putting a Faberge egg in a Ziploc bag. They may be an added benefit for the occasional jostle when on a trip to the zoo, but I wouldn't trust it to keep my camera safe long-term.

Next up on the list is the gear bag. Gear bags are very popular and come in a wide variety of sizes and configurations. Some gear bags are really nothing more than a glorified soft-sided lunch bag, while others are as large as a duffle, with multiple compartments and removable sections. The bag in Figure A is typical of the standard gear bag.

FIGURE A

The gear bag, although popular, is essentially a purse for your camera. Click picture for a larger image.

A sub-category of the gear bag is the gear backpack. Personally, I've always thought the gear backpacks were pretty neat. As you can see in Figure B, the gear backpack has convenient little compartments arranged in such a manner as to evenly distribute the weight of your gear.

FIGURE B

The gear backpack is essentially a gear bag turned on its side. Click picture for a larger image.

Although I wouldn't rely on a gear backpack for permanent storage and transportation of my equipment, it's very convenient for a location shoot, particularly if you have to trek to a remote spot. Many of them even have external straps to secure a tripod.

For true full-time protection and safety, I only trust a hard-shell case. Hard-shell cases generally come in either plastic or metal, and can be foam-lined or not. In truth, the plastic cases would be more desirable than metal ones. The plastic cases are constructed of a high-impact plastic for strength, and usually have an O-ring seal to make them waterproof. Depending on what you put in them, plastic cases will in all likelihood remain buoyant if immersed in water.