Your first big choice in your hunting knife pursuit is between a folding or a fixed blade. A fixed blade knife has a blade that's permanently affixed in the open position. Because there are no moving parts in the fixed blade knife, they're generally considered strong and reliable. There are downsides, however. Because the knife is always open, you have to carry it in a sheath and wear it. This makes it bulkier than a folding knife with the same size blade.
The blades of a folding knife fold back into the handle. It also has a locking feature that prevents the blade from accidentally closing while you're using it. Because the blade folds back into the handle, the knife is more compact and can be carried more easily. But this design feature is also the folding knife's biggest drawback. Its hollow handle and the pivot point where the blade folds are weak points -- the folding knife isn't as strong as a similarly-sized fixed blade knife.
One advantage of the folding knife is blade choice. Not all folding knives have more than one blade, but many do. Some people view this as a benefit. But, the truth is, if you choose the right hunting blade, you shouldn't need more than one. Also, there are several fixed hunting knives on the market that allow you to change out the blade. You can only use one blade at a time, but you can carry a selection with you.
The choice between fixed blade and folding blade is largely practical. For the serious hunter who wants a dedicated hunting knife, a fixed blade design is the best choice. For a person who only hunts occasionally, who will use the knife for other purposes and prefers to carry it in a pocket, the flexible blade handle may make a better choice.