Resistance bands are the perfect addition to your home gym. You can fold them and store them anywhere. You can buy several of these items with different widths to vary the load. You can do virtually any free weight exercises using the bands. You can also use the thinnest ones for warm-ups and stretches.
For example, you can step on one end and hold the other end with your hands. Do bicep curls in this position. Adjust your hold to do tricep extensions, rows, weighted squats, chest press, and so on. The possibilities are endless.
If you are trying to build muscle, then this is a great exercise tool to use. The resistance band transformation will astound you. There is no need for heavy equipment and large cash outlays just to get the body that you have been dreaming of.