When a decision is made in court it is made available as an Unreported judgment. If the case is deemed important, and only a small proportion are, then it may then be published in a Law Report series, thus becoming a reported judgment. These judgments are ones that:
There are two types of Law Report series, Authorised and Unauthorised.
If there is an authorised version of a judgment available, this should be cited in preference to the unauthorised version.
How do you know if it is authorised?
Check the list of authorised law reports
Some cases will be reported in multiple law report series, and this can make it easier to locate the judgment if the fulltext of the authorised series is not available.
If you are simply wanting to read the judgment, then it won't matter which version you read, but you should always use the authorised version (where available) when citing the case in an assessment or to the court.
Are the following citations for authorised or unauthorised judgments?