In a TV studio there will be several cameras filming the same action from various vantage points. This enables a Director to cut between viewpoints to add interest and new perspectives –long shot, side on, close–ups etc.
For most corporate work we use one camera and in a controlled environment we may ask someone to repeat an activity three or four times while we take shots from different angles. In the edit we can then mirror the variety of multi-camera views.
Sometimes however, notably in uncontrollable situations such as live uninterruptible events, there is no opportunity to re-film the action and then we recommend two or more cameras.
Sometimes we use a remote second camera to film a wide shot continuously (the safety shot) while a manned camera takes a mix of shots. This is a very cost effective solution.