Hello, I'm glad to answer your question. Smith is a kind of equipment, which plays a protective role. Generally, gyms have this equipment. For example, when you do bench presses and squats, you want to add weight and sprint, but there is no one around to protect you. At this time, you can use Smith equipment to help you complete the heavy training. It is best to use Smith under the guidance of the gym coach to avoid injury due to improper use!

I hope my answer can help you, and I hope it will be adopted!