What is the main difference between the Earth and other planets?

The Earth has many differences from the rest of the planets in our solar system. The first is its size: it is large enough to have strong gravity and hold on to the atmosphere. Secondly, this is the ideal distance from the Sun, due to which enough heat enters the surface, but radiation is not harmful to life. Scientists suggest that other solar systems may also have planets with similar conditions. But the existence of life makes the Earth unique among all space objects known to man.