In this tutorial, I demo how to pressure can fresh green beans from our garden.
Pressure canning is best done for foods with low acidity. Many foodstuffs can be pressure canned. - including meat and fish!
A water bath is best for canning foods that have higher acid content like tomatoes, jams, and jellies. Water baths only get as hot as 212°F/100°C whereas water in a pressure canner can achieve temperatures of around 240°F/115.6°C. This is to sterilize the contents to keep from harmful bacterial growth from forming such as cover time.
There are tons and tons of information on pressure canning and the amount of pressure needed and time varies based on what you are pressure canning and the amount.
Be sure to consult reputable resources for such recipes and techniques. The University of Minnesota Extension Canning Quick Reference Chart is a good start: https://extension.umn.edu/preserving-and-preparing/canning-quick-reference-chart