What is accretion, and how did it form the Earth?

Accretion: the coming together and cohesion of matter under the influence of gravitation to form larger bodies.

After the Sun was formed, the remaining gas and rocks and ice and stuff spun around the Sun began to clump up(accretion). Bounded by increasing gravity, larger and heavier celestial bodies formed, one such body became what is now known as Earth.

Accretion is the process by which celestial bodies, such as planets, grow larger by gradually accumulating matter through gravitational attraction. The Earth formed around 4.6 billion years ago through accretion, as dust and gas in the early solar system coalesced into larger and larger bodies, eventually forming the Earth. As smaller particles collided and merged, they formed planetesimals, which further aggregated to form protoplanets. These protoplanets then collided and accreted to form the Earth.