There are some charges, such as domestic violence, that require you to be held in custody until you go before a Judge. For other cases, the court may set a bond amount to secure your attendance at future court hearings. The type of bond can vary: posting the full amount in cash, using a bondsman, posting 10% of the bond in cash, or simply signing a piece of paper promising to come back to Court (O.R. bond).
If you are held in jail until your arraignment, the Court will set a bond amount at this hearing. It can be very important to retain an attorney prior to the arraignment. Your attorney can obtain information and present it to the Judge for consideration so that you may receive a lower bond.