Hi And Welcome to ATP.
Beans and peas, and all legumes, are "nitrogen fixers" meaning they snag nitrogen out of the air and store it in their roots. Then you plow under those roots and the nitrogen goes into the soil to feed the next generation of plants. An important consideration if you are an organic farmer.
But legumes don't always produce extra nitrogen so someone has figured out that farmers can help that process along by treating their seeds with an inoculant - a bacteria that helps the plant store even more nitrogen. But, you have to get the right inoculant for it to work. And if you are not an organic farmer, you don't care how much nitrogen the plant stores. (By the way, the nitrogen is stored in little bulges on the roots - like mini-potatoes.)
Luckily, legumes are smart and know how to do that on their own. They will grow an adequate amount of their own bacteria and start snagging the nitrogen out of the air all by themselves. You don't need to treat them with the inoculant; they will make enough nitrogen for what they are intending to do: produce beans and peas.
Daisy