How was the earth's formation different or similar to the formation of the other planets?
The formation of the inner four planets, which include Earth, were similar.
The solar system formed from a disk of material which was orbiting the Sun. The inner part of the disk was mainly dust as gases get heated and blown further out by the Sun's heat and the solar winds.
In the inner solar system, dust particles collided and clumped together. They formed larger and larger rocky objects. These clumps finally clumped together to form the rocky planets, Mercury, Venus, Earth and Mars.
Of the inner planets Venus and Earth and about the same size. Mercury and Mars are much smaller.
In the outer solar system, volatile materials were solid. Also, gases were trapped inside ices. These materials also clumped together. These ultimately formed the giant planets. Jupiter and Saturn are gas giants which are mainly Hydrogen and Helium. Uranus and Neptune are ice giants. They are also mainly Hydrogen and Helium but also contain quantities of water ice, methane and ammonia.
It is also thought that soon after formation, Earth was hit by a Mars sized object which lead to the formation of the Moon.