In typical criminal law, time served is an informal term that describes the duration of pretrial detention (remand), the time period between when a defendant is arrested and when they are convicted.
A sentence of time served means that the defendant has been sentenced to confinement, albeit retroactively fulfilled by the pretrial detention; therefore, the defendant goes free.
[1] A sentence of time served may result from plea bargains in which in exchange for only receiving a sentence that involves no additional period of incarceration, a defendant accepts a guilty plea.
[2] Statistics released in 2020 by the Victorian Sentencing Advisory Council show that 67% of people sentenced to prison in Victoria, Australia in 2017–18 spent at least one day in remand, up from 47% in 2011–12.
The council called the over-detention a "matter of concern", as the defendant spent longer in detention than the ultimate duration of the sentence.