What is simultaneous interpreting ?
Interpreting while the delegate is speaking.
The interpreter works in a soundproofed booth with at least one colleague. The speaker in the meeting room speaks into a microphone, the interpreter receives the sound through a headset and renders the message into a microphone almost simultaneously. The delegate in the meeting room selects the relevant channel to hear the interpretation in the language of his/her choice.
There are many different possible configurations of languages or language regimes.