There are many reasons to can your own food, not the least of which is a huge cost savings! When you grow your own produce or buy in bulk, you can save money over the grocery store alternatives. However, if you've ever grown your own garden you know when "harvest" time is upon you it can be just about impossible to eat all the fruits of your labors. Through the centuries, humankind has come up with some pretty ingenious ways to preserve this bounty! One of the simplest methods is lacto-fermentation (which is enjoying a bit of a rennaisance!) Add to that drying, dehydrating, smoking, salting, freezing, freeze drying or just putting it into a hole in the ground!
These different methods have varying degrees of effectiveness and some are basically inaccessible to the general public. (Not many of us can afford the $3000 + for a home freeze drying machine!) While these preservation methods will keep food "edible" for quite a while, some preserve more of the nutrition than others while a few sound down right dangerous! Think water-glassing an egg!
Currently, canning and freezing are two of the most common home food preservation methods, but it wasn't always this way! Canning was first developed in answer to a challenge issued by Napoleon Bonaparte who offered a reward to anyone who could reliably preserve food for his army. Even so, it took another hundred years for canning to catch on. Today, there is canned food in just about every house in America!
If you're ready to start home canning, this video from Jamie at Guildbrook Farm shows canning basics for beginners focusing on tools, equipment, terminology, and resources. This is, IMHO, one of the best canning basics videos out there!