Short answers, pulled from the story.
Roman citizenship, or civitas, was a privileged legal and political status that granted rights to property, legal protection, voting, and public office. It applied to free individuals and came in several gradations, including full cives Romani, Latin rights holders (Latini), and allied citizens (socii), with exact rights depending on gender, class, and political status.
Full male Roman citizens held the rights to vote, hold office, own property, enter contracts, appeal court decisions, sue and be sued, and receive immunity from certain local taxes. Following the Porcian Laws of the early 2nd century BC, they could not be tortured, whipped, or sentenced to crucifixion, and could commute a death sentence to exile.
The Edict of Caracalla, officially the Constitutio Antoniniana, was issued in AD 212 by Emperor Caracalla. It granted full Roman citizenship to all free men in the empire and extended equivalent rights to free women, excluding only the dediticii and freed slaves.
Roman citizenship could be acquired by birth to two free citizen parents, by completing service in the non-Roman auxiliary forces, or through election to public office in a provincial city under Latin law. The Lex Julia of 90 BC also granted citizenship to Latini and socii states that had not participated in the Social War.
Roman women held a limited form of citizenship: they could own property, conduct business, and seek a divorce, but could not vote or hold public office. They generally remained under the guardianship of a pater familias or male relative, and the scope of their legal rights varied across different periods of Roman history.
The Social War of 91-87 BC was a revolt by Rome's Italian allies, the socii, who were dissatisfied with their limited rights and the growing military demands of the legions following the Jugurthine War and the Cimbrian War. It ended with the Lex Julia of 90 BC, which granted full cives Romani status to all socii and Latini states that ceased hostilities, effectively eliminating those categories as legal distinctions.