Pre-workout supplements are typically a combination of ingredients that are intended to help your body operate it's best during physical activity.
Depending on the type of activity you are doing, or the goal of your workout, the type of pre-workout you want to use can vary and the ingredients you will want to look for can be different.
Sure, there are some ingredients of pre-workouts like Creatine, Beta-Alanine, and others that have many benefits and can improve many types of workouts... thus they are very popular and in most pre-workouts.
But the key idea to understand is that pre-workout supplements are intended to give your body a boost in energy, strength, endurance, and performance.
By using a pre-workout supplement ... over time, you can see faster progress than you would without it.
The more you can accomplish while training your body in a workout, and then recover properly and fuel your body with good nutrition... the stronger your body will become for future workouts.