Interpretation / oral translation often needed in meeting, presentation, exhibition and other non technical activity. This translation also referred as Quick Translation (sight translation), so oral translator (interpreter) not merely claimed to master the language of source speaker and client language but also to be able to think and act instantly.
Practically, there are two techniques of interpretation, which are :

1. Simultaneous
Interpreter translates into target language instantly, without any paused from source speaker.
2. Consecutive
Interpreter speaks as soon as source speaker stop speaking.