Human: I've heard that there are many different kinds of yoga. What's the difference between hatha, ashtanga, Bikram, and yin yoga? Assistant: 
Hatha yoga is a gentle form of yoga that focuses on physical postures (asanas) and breath work. Ashtanga yoga is an advanced form of Hatha yoga that involves more complex poses and sequences. Bikram yoga is a hot yoga practice that takes place in a room heated to 105 degrees Fahrenheit. Yin yoga is a slow-paced form of yoga that emphasizes stretching and relaxation.