The word driver is more general - anybody who drives a vehicle is a driver. You are a driver when you are driving your car. Some people work as bus drivers and taxi drivers (the drivers of trains are usually called conductors).
A chauffeur is a person who is employed to drive a car for a private individual. Rich people and celebrities often have chauffeurs so that they do not have to take public transportation, or drive themselves.
All chauffeurs are also drivers; not all drivers are chauffeurs.
Cardio is crucial to any mans workout plan, but it can be detrimental when done at the wrong time. Completing a 30 minute jog before a set of heavy squats may increase your heart rate and act as a warm up, but by the time you get under the bar youll be fatigued which can lead to poor form or worse, potential injury. Instead, get your form intensive lifting session done first, and then hit the cardio area.