It's really a combination of time and temperature that does the work. For instance, you can pasteurize at 130 F, it just takes a several hours. Most pathogens don't grow well outside of their preferred PH range, which is why pickling works. Salt will desiccate their cell walls, too.

The reasons canning is done at a higher temp is that the food is being sterilized, not merely pasteurized. Pasteurization will result in as much as a 7D reduction in the amount of pathogens but since some of the most deadly thrive in anerobic conditions (eg a sealed can), given enough time even a very small amount of bacteria would be able to multiply to dangerous levels. This is why pasteurized milk won't keep forever, and why meats prepared sous vide are generally only considered safe to store under refrigeration for a few weeks. Heating to around 240 degrees for a few minutes kills "virtually" everything in the can. And of course, since water won't get hotter than roughly 212 F at atmospheric pressure you must use a pressure cooker to raise the temps to that level. Commercial canneries actually use equipment that agitates the cans as well, reducing the amount of time it takes to heat all the contents evenly.

Once food has been vacuumed and subjected to the heat of pressure canning it's shelf stable. While quality will eventually suffer food that's been properly canned can be safe to eat for over 70 years. MREs are another type of can; the retort pouches used to store them are actually called "flexible cans."