'Cohort' in the Bible

Now [there was] a certain man in Caesarea {named} Cornelius, a centurion of what was called the Italian Cohort,

And [as they] were seeking to kill him, a report came up to the military tribune of the cohort that all Jerusalem was in confusion.

And when it was decided [that] we would sail away to Italy, they handed over Paul and some other prisoners to a centurion {named} Julius of the Augustan Cohort.