nothing
Gravity.
gravity
Gravity
the suns gravitational pull pulls them toward it but the planets try to escape its gravity
The question probably means "What keeps the planets in orbit around the Sun?" The answer to that is : The Sun's gravitational attraction provides the force needed to keep the planets in orbit. This force doesn't pull the planets any closer to the Sun, but it stops the planets moving away (at a tangent to their orbits) due to their own velocities.
The Sun's Gravitational pull keeps the planets orbiting it, not flying into deep space.
The planets are kept in orbit around the sun due to the gravitational force between them. This force, which is a balance between the planet's inertia and the sun's gravitational pull, keeps the planets moving in a stable path around the sun.
The gravitational force exerted by the Sun keeps all the planets in their orbits. This force balances the planets' tendency to move in a straight line and keeps them moving in elliptical orbits around the Sun.
gravity
Gravity.
gravity
Gravity