In Cicero's career, he holds many posts. here is a quick list of some of them, thanks to the Durant's Story of Civilization.
Consul: you will remember is the head of government. There are two. they hold office for only one year. After the end of their term, they are automatically members of the Senate for life, but can't hold the office of consul again for 10 years.
The Senate was one of two lawmaking bodies: only patricians could be members. The other, the Tribunal, was elected by the plebes (ordinary people) but could only veto, not propose and vote on laws. By custom, the Senate had become supreme, combining what we would call executive, legislative, and judicial functions in one body. Durant claims that given how much power they held, they did very little abuse of it and praises the quality of men that were in it.
Lesser offices, many of which, Cicero held (starting with the lowest):
Quaestors: managed the expenditure of state funds and assisted in preventing, punishing crime.
The four Aediles were charged with the care of buildings, aquaducts, streets, markets, theater, brothels, saloons, police courts, and public games.
The four Praetors led armies in war, and in peace acted as judges and interpreters of law. They had a special guard called the Praetorian Guard.
The two Censors: did just about anything else (including the census, building the aquaducts and the Appian Way, and approving the candidates for consul).