There are 5 ways to typically bail someone out who has been arrested.
1) Directly pay cash bail to court.
2) Pay a bail bondsman to post a bail bond or surety bond.
3) Use real property as collateral in a "property bond".
4) Citation Release issued by law enforcement releasing defendant and informing them they must appear before the court at a later date.
5) After going through pre trial process, defendant released on their own recognizance or promise to appear at scheduled dates. Sometimes called "OR" for short.