I am a huge proponent of body-weight based exercise. It’s convenient because you can exercise completely on your own schedule right from home. It’s cost efficient because, well, all you really need is yourself (although I also recommend a pen & paper to jot down how many reps you do!). Most importantly though, it’s effective. Machines are fantastic tools and the atmosphere in many gyms is often inspiring, but personally, I’ve gained all my strength completely through my yoga practice (which actually uses most of these regularly!).
I hope these explanations not only help you navigate the world of at home workouts, but also inspire you to try a few and maybe even design a workout of your own!