Anyone who is charged with an offence and awaiting trial is considered to be 'on bail' whether or not they had a formal bail hearing. There are several types of releases, which will depend on the seriousness of the offence and background of the person being charged.
If someone is charged at the scene of the offence, they may simply be released without conditions and given either a Summons to appear in Court, or Promise to Appear which outlines their next court date.
The first step of the process is the incident itself. A charge is laid by the police which sets the system in motion. The individual charged will then be compelled to appear in court by one of several means. If the police release the person from the scene, they may issue a summons or a promise to appear. If they are not released, they could be held for bail.