Citizens are people who joined the Federal Service and were honorably discharged and given franchise. Joining the Federal Service does not necessarily mean the military, and applicants may be assigned to any field where they sacrifice their time and effort for the Federation (Teaching, any of the civil services, experimental test subjects, etc), though military service is the most glorified. It all falls under Federal Service.
- They are able to vote in Federation elections.
- If they wish to attend college, they are given lower or no tuition fees. (Film universe)
- They are given special permission to have more than two children. (Film universe)
It should be noted that members of the military are not given franchise while still serving, they must retire to be able to vote.
"A citizen accepts personal responsibility for the safety of the body politic, defending it with his life, a civilian does not." - Johnny Rico while still a student.
"A citizen has the courage to make the safety of the human race their personal responsibility." - Johnny Rico after weeks of military service.