What is state of nature according to Thomas Hobbes?

Hobbes says that the State of Nature is a hypothetical state of affairs existing prior to the formulation of 'society' (which arises with the signing of the hypothetical 'Social Contract').

In the State of Nature, Hobbes thinks everyone acts selfishly. He calls it a war of all against all, and life in the State of Nature is 'solitary, poor, nasty, brutish and short'.