Will resistance bands build muscle?
Yes resistance bands are a great way to build muscle. With that being said it is also not the best way or the worst way. Resistance bands used in addition to some sort of weight training will produce the best results.
Essentially, resistance training is a way to change fat and turn it into muscle. When using resistance bands or some form of resistance and you exercise with a high amount of reps you are activating more muscle fibers more consistently which will in turn burn the surrounding fat and develop stronger muscle.
Think of it like cardio for one specific muscle or muscle group at a time. The goal is to implement a high amount of reps and feel the light but consistent burn in your targeted muscle.
If you implement resistance training with weight training you will notice that your muscle develops in a way that gives you the edge over those who only train with weights. Your muscle fibers will develop thoroughly throughout the muscle rather than balling up and growing with no flexibility.
If you think you want to get started check out this resistance band set Elastic/Resistance Bands 9 pc Training Set It includes everything to help you get started with resistance training.