I don't understand the meaning of the following sentence

"But the magistrate convicted the monk for soliciting a prostitute and put him on bond for 12 months."

What is the meaning of the phrase "on the bond". If it refers to a contract then what kind of contract is it?

can anyone help?

thanks in advance
The monk has had to deposit money with the court in order to help ensure that he does not commit another crime within 12 months:

'Judge Julie *** placed Sheather on a $200, 12-month good-behaviour bond but no conviction was recorded.'

I am not sure whether the phrase 'on bond' is used in the cases where no money is required-- some first offenders in minor crimes are released 'on good behaviour'-- meaning the same thing: they must not commit another crime of any kind within the stipulated period.