The pullout method also known as withdrawal is a practice of pulling the penis out of the vagina just before ejaculation to prevent pregnancy. The ejaculation has to happen away from the vulva and the inner thigh. This method is not very reliable as it requires the person to have a very good self control and self awareness of when they ejaculate.
The pullout method alone does not protect one against STIs or pregnancy.
Sources:
https://www.healthline.com/health/can-you-get-pregnant-from-the-pull-out-method#overview
https://www.webmd.com/sex/birth-control/pull-out-withdrawal
https://www.mayoclinic.org/tests-procedures/withdrawal-method/about/pac-20395283