Peas are Pulses. The term pea typically refers to garden peas which like all pulses are high in protein. Garden peas are eaten sometimes green and immature, sometimes still in the pod, that's known as mangetout. Sometimes garden peas are eaten as mature seeds, that's known as yellow split peas.
Other pulses with round seeds like the garden pea are also usually called peas, that includes cowpeas and others. Chickpeas are a bit of an exception, they'round and British people call them peas, still Americans frequently call them garbanzo beans.