A discourse community is simply a community that has its own ways of communicating and common interests. It has its own traditions and ways of indoctrinating new people. They often come up with their own slang and training process.

A strong example of a discourse community would be the Marine Corps. They have their own indoctrination process, their own terminology and their own common goals. You are expected and trained to assimilate into their culture.

A more moderate example would be learning to work at an auto parts store. It doesn’t require the 24/7 dedication of the Marine Corps, but you do have to spend time to learn what auto parts to look for. The customers always appreciate it when they need a O2 sensor and you are able to understand what they are asking you. You don’t need to be an expert mechanic, but you do need to understand their language and interests. These customers may have their own slang, and they will expect you to understand it.

Since I work in EMS, I am not part of a discourse community, but a fragmented group of communities. There are many different definitions of an EMS community, and they all have their own forms of communication. They tend to vary by region and their exact goals. An EMS agency is rural Ohio would have a different form of communicating then one is Lima. Also, when you begin to work in one, then you tend to stay in that community that they are familiar with.