Philosophically, bandha means “bound” and in yoga, we are working toward liberation. 

4 Yoga Bandhas- Locks

1. Mula Bandha is the root lock. It is the concentration of the perineum, turning the energy upward. I think activating the mula bandha feels like a kegel, a strengthening of the anal wall, and I like to feel this perineum lock when standing in balances like vrkasana, tree pose.

2. Uddiyana bandha, the abdominal lock, is pulling in abdominals inward toward the spine. I had a yoga teacher use the example that there is a string attached to the belly button, and it tugs our center to the spine. My favorite way to feel this engagement is in forward folds. When I lift the uddiyana bandha, a hollow space is created. We fold into this space and increase the length of the spine in the forward fold.

3. Jalandhara bandha, the chin lock, holds the energy in the throat and chest. I like to feel this lock when energizing in Dandasana. We can feel the whole length of the spine while sitting tall on our sits bones and a gentle tuck in the chin.

4. When we lock all three Bandhas at once, they form the Maha Bandha, meaning the great lock. this releases stored prana and allows it to flow freely through your the body.

“As the mind, so the man; bondage or liberation are in your own mind. If you feel bound, you are bound. If you feel liberated, you are liberated. Things outside neither bind nor liberate you; only your attitude toward them does that.”
-Swami Satchidananda
The Yoga Mind (paid link) by Rina Jakubowicz 

Learn more about the classical yoga to feel the 4 yoga bandhas in action!