Bandha (Sanskrit: बन्ध -binding, bond, arrest, capturing, putting together etc.) is a term often employed in relation to yogic discourse and instruction. The term denotes a binding, lock or bondage that may be either internal or external to the body. Bandha may be defined as a particular focused and intentional action involving pressure, contraction or force on the muscles or some other bodily or sensate phenomena. In yogic traditions, bandha are to be studied, maintained and held principally whilst engaged in pranayama.
In Jainism, bandha, refers to the karmic process of binding of material karmic particles to the soul consciousness. This bondage is on account of kasaya or passions of the soul. As per ancient Jain text of Tattvarthasutra, bandha is one of the tattva or fundamental truth of this world. As such the samsaric soul is always found in bondage with the karma since time immemorial.
Various bandhas are described and elucidated in Yogic texts and discourse. However, rarely is an exegesis of Bandha provided. Bandhas have been described in Hatha Yoga Pradipika in the chapter relating to Mudras. Ten mudra are codified in this treatise. Of marked importance, the chapter describes all bandha as mudra.
Definition courtesy Wikipedia.