A Class or Group Action is a Court procedure which allows people with similar claims against another party to bring their action in one Court Proceeding rather than requiring them to go to the cost (and take the individual risk) of commencing their own claim.
In Australia, the law provides individual Group or Class members the opportunity to Opt Out of the Proceedings if they do not wish to participate or wish to bring their own individual claim.
The benefit of Class or Group Actions is that it means that claims that would otherwise not be economically viable for a person to bring on their own behalf are able to be gathered together so that the costs and risks can be shared among a larger group of people with similar claims.