The larger an objects mass, the bigger its gravity. Obviously the sun has an enormous mass in comparison with earth. The strength of gravity is huge here, hence the fact the whole solar system orbits it. Likewise, Jupiter has a much larger mass than earth. Whilst not nearly as strong as the sun, the gravitational strength on Jupiter would be a lot higher than on earth. Mars is slightly smaller than the earth, and as such has slightly less mass. As a result, the strength of gravity is similar, but not quite as strong as on earth.
Hope this helps.
Hope this helps.