Word Distinction: Earth, Land, Soil, Ground, Floor

The surface of the world, when compared with the sea, is called the land, but when compared with the sky or space it is called earth or the Earth:
After a week at sea, the sailors saw land.
After a week in space, the spacecraft returned to earth.
An area considered as property is a piece of land:
the high price of land in London
The substance in which plants grow is the soil or earth:
a tub filled with soil/earth, or (when we think of it as having an area) ground
a small piece of ground where I could plant a few potatoes
But when we are talking about large areas used for farming, we say land:
There is good land here for growing corn.
The surface we walk on is called the ground, but when this is inside a building, it is the floor:
The horse fell to the ground.
The plate fell to the floor.