Resistance bands and suspension trainers are often grouped together because both are portable gym accessories. Mechanically, they are different tools. A resistance band creates elastic tension as it stretches, while a suspension trainer uses straps, handles, an anchor point, and body angle to load movement with bodyweight.
That difference changes the resistance curve, setup, stability demand, exercise selection, and how difficulty is adjusted. Bands can assist or resist movement through stretch. Suspension trainers make position and balance central to the exercise. The useful comparison begins with where the resistance comes from.