Bail

Bail is some form of property deposited or pledged to a court to persuade it to release a suspect from jail, on the understanding that the suspect will return for trial or forfeit the bail (and possibly be brought up on charges of the crime of failure to appear).
http://en.wikipedia.org/wiki/Bail

The main reasons for refusing bail are that the defendant is accused of an imprisonable offence and there are substantial grounds for believing that the defendant would:
Abscond
Commit further offences whilst on bail
Interfere with witnesses

The court may also refuse bail:
For the defendant's own protection
Where the defendant is already serving a custodial sentence for another offence
Where the court is satisfied that it has not been practicable to obtain sufficient information
Where the defendant has already absconded in the present proceedings
Where the defendant has been convicted but the court is awaiting a pre-sentence report, other report or inquiry and it would be impracticable to complete the inquiries or make the report without keeping the defendant in custody
Where the defendant is charged with a non-imprisonable offence, has already been released on bail for the offence with which he is now accused, and has been arrested for absconding or breaching bail

The court should take into account the:
Nature and seriousness of the offence or default (and the probable method of dealing with the defendant for it)
Character, antecedents, associations and community ties of the defendant,
Defendant's bail record, and
Strength of the evidence