Like the sasae ashi these are judo footsweeps.
The goal is to first get a grip on your opponents upper body, head, or arms.
Then throw a soft kick out to the side and swing it into your opponent's lower legs or feet.
This will push his feet in one direction while you rip your opponent upper body in the opposite direction.
This will cause him to immediately lose balance you and pressure and weigh him into the ground.
You do not lift after sweeping the legs.