Pope Francis is a Jesuit, what is the difference between a Jesuit and a Franciscan? What order are you?
There are hundreds of different religious communities for men and for women which vary mostly by charisms and ministries. The Jesuits were founded by Ignatius of Loyola to serve in the defense of the church against heresy and are typically educators and scholastics. The Franciscans were founded by Francis of Assisi to serve the poor and to set a spiritual example of the connection between God and the poor. Both communities have priests and lay brothers (non ordained men) who serve in their ministries. Some communities have only lay members, and some communities have only ordained members.
I am not a member of a religious order; I am a diocesan (or secular) priest. Members of a religious community make a promise to the community to serve the community for the rest of their lives. They promise obedience to the community’s superior (elected leader). In the case of the Jesuits they also take a vow of obedience to serve the Pope. Where and how they serve depends on the community’s missions but can be anywhere in the world. As a diocesan priest I made a promise to serve the people of my Diocese for the rest of my life, thus under normal circumstances I would never serve outside there. My promise of obedience is to the local bishop and his successors.
Most religious communities take a vow of poverty and as such do not get paid directly. Monies earned through ministry go to the community to provide for everyone in the community. Diocesan priest do not take a vow of poverty and are paid directly. Most members of a religious community then would not pay taxes as they have no legal income. Diocesan priest, on the other hand, pay income taxes and if they choose they may pay into Social Security but they pay 100% of the social security taxes.
When a member of a religious community retires the community takes care of them for living expenses. When a diocesan priest retires he is typically on his own with the monies he has been able to save to live on. (Like others in our world, some are thrifty and others are not.) This is why my diocese has the PHRA (Priests Health and Retirement Association) to help provide retired diocesan priest with medical and retirement support, otherwise some would have no medical assistance when they retire.