The basic unit for interpretation is an hour/day.
We distinguish the following kinds of interpretation:
Consecutive interpretation
The interpreter interprets into another language the logical unit uttered by the speaker.
Simultaneous interpretation
IN this kind of interpretation, the interpreter interprets at the same time as the speaker is uttering sentences without any breaks (but slowly). Special rented equipment is used for this kind of interpretation.
Chuchotage
The interpreter sits or stands next to the target language audience and quietly but clearly, whispering, interprets while the speaker is speaking.
In case of interpreting that includes longer time periods (longer than 1h/ 1.5h) it is necessary to hire two interpreters.