hath yoga

its a descipline of the yoga that puts boundaries in the yoga by forcing the body and mind to attain a particular goal.
the tools of hath yoga are

neti

vat neti

jal neti

ghrut neti

dhauti

vat dhauti

jal dhauti

vasti

nyoli

nyoli position.

bandha

uddiyan 

jalandhar

tribandha

mudra

khechari