For most people, it simply isnt practical to get gym equipment for their home. The equipment is expensive, and you probably dont have anywhere to put it, and its certainly impractical to buy and store the wide variety of machines that are necessary for a properly balanced workout.
For this reason, most people choose to join a gym. For either a per-visit fee or a monthly subscription fee, you get to share the equipment with other people, paying a fraction of the price of what its worth. You also get to exercise in a specially-designed, luxurious air conditioned environment, with qualified trainers on hand to help you get the most out of the equipment and make sure you dont hurt yourself.
However, gyms also have a bit of a reputation for being scammers: the big chains are very sales-driven, trying to sign people up for far more expensive monthly memberships than they need, and relying on peoples guilt about not going to the gym to stop them from cancelling the expensive commitment.
For this reason, you really need to know what youre getting into before you join a gym. Avoid offers that seem too good to be true, and always pay the per-visit fee to go in and...