Garages and workshops are often referred to interchangeably, but there are some differences. Garages are built specifically to house vehicles, and while you can add a shop to a garage, you are still working in a garage. Since they are intended to house vehicles, they often are not well ventilated or insulated, so they can be much hotter or colder than a house or workshop, depending on the season.
A workshop is intended to be worked in for a length of time, so they have the right insulation and ventilation. They also are intended to be a shop, so they are designed with that functionality in mind. For more information, our post “Do You Need a Garage or Workshop?” offers a more detailed analysis between the two and design options.