What is Hatha Yoga? Essentially, it is the foundation of yoga. Every style of yoga stems from the basic tenets of Hatha Yoga
What Is Hatha Yoga?: A Definition

In Sanskrit, the word hatha is a combination of ha, which means sun, and tha, which means moon. Yoga means to yoga, or join together. Thus, hatha is the combination of the masculine energy of the sun and the feminine energy of the moon, creating balanced power.

Classical Hatha Yoga includes a number of factors, including:

The Eight Steps, or principles
Asana, or postures
Shatkriya, or purification
Mudra, or poses
Pranayama, or breathing exercises
Learn more about the origins of Hatha Yoga in this article.

The Eight Steps
In order to gain a better understanding of Hatha Yoga, learn more about the methodology, known as the eight steps or limbs, of the practice.

Yama: personal conduct and truth
Niyama: observance
Asanas: physical practice
Pranayama: breath control
Pratyahara: release of the senses
Dharana: focus
Dhyana: meditation
Samadhi: the heightened consciousness
Learn more about the eight limbs of Hatha Yoga in this Yoga Journal feature.

Asana
Most people who encounter Hatha Yoga for the first time usually do so through the asanas, or physical practice. Practicing asanas restores the body and improves health. Here are some of the more familiar Hatha Yoga asanas:

Downward Facing Dog Pose
The Warrior Series
Lotus Pose
Child's Pose
Bridge Pose
Learn more about Hatha Yoga poses by reviewing the slideshow from LoveToKnow Yoga.

Shatkriya
Shatkriya encompasses six actions designed to detoxify the body. You may have already tried a few of these methods and not realized they were part of a much larger practice.

The six kriyas are:

Dhauti: an internal cleanse prompted by swallowing muslin or salt water
Basti: colonic irrigation
Neti: nasal and throat cleansing
Tratak: eye cleansing
Nauli: organ cleansing through abdominal manipulation
Kapalbhati: lung cleansing
Learn more about kriyas from the Journal of Yoga.

Mudra
Another aspect of knowing what is Hatha Yoga is the mudra poses. Mudras relate to the energy of your body or your mood. If you've seen pictures of yoga practitioners sitting with legs crossed and their hands in different positions, then you've seen examples of mudras. While most stimulate acupressure points in the hands and fingers, some mudras involve the entire body.

Asanas, or postures, are only a small part of a complete Hatha Yoga practice.
Here are a few hand mudras:

Anjali Mudra, designed to center the mind and open the heart
Jnana Mudra, improves concentration
Lotus Mudra, helps relieve despair
Abhaya Mudra, which means no fear
Here is a helpful pictorial of mudras.

Pranayama
Another important element of Hatha Yoga is the practice of pranayama. In yoga, air is the life force of the universe. Learning better breathing techniques enhances not only your physical yoga practice, but also your overall wellbeing.

The three most common pranayama techniques are:

Dirgha pranayama
Nadi shodhana
Ujjayi
Here is a simple technique for Dirgha Pranayama, also known as the complete breath.

Sit tall in Lotus Pose.
Place your hands on your stomach, close your eyes, and inhale deeply through the nose. #Expand the rib cage as you fill the diaphragm with air. Exhale slowly through the nose.
Move your hands from your belly to your heart and repeat the breathing sequence. Let #your chest rise as your rib cage expands. Exhale.
Place one hand at the base of your throat, fingers along one side of your neck, thumb on the other. Inhale deeply, letting your upper body fill with breath. Exhale.
Finally, control your breath by counting to 10 for both inhale and exhale breaths.