We explained above that asanas are 1 of the 8 limbs of yoga and the yoga practice that you probably commonly think of when you think about yoga. Asanas refer to the actual bodily poses involved in yoga. They're more than just stretching or strength-building exercises, but are purposeful in centering and aligning the body, and creating a meditative flow of energy between the body, mind, and spirit.
They can be relaxing but still difficult, and increase flexibility, strength, and stimulation of the circulatory and immune systems. Different forms of yoga are centered around different asanas, but some commonly known asanas are the headstand, the cobra, the downward facing dog, and the warrior pose.