A company's vision statement is its goal for the long term. It is an idealistic or aspirational planning tool, often describing lofty goals that the company is unlikely to achieve. It usually complements the mission statement and the values statement.
While a mission statement says what a company will or will not do, and a values statement says what skills or attributes the company culture values, a vision statement says where the company wants to go in the future.
The vision statement may be just a few words or up to a few sentences. It's rarely longer than a paragraph with a few bullet points.
Companies use a vision statement to describe a "Big, Hairy Audacious Goal" (BHAG), which is a planning tool used to help people think ambitiously about future possibilities.
Vision statements usually describe external or internal targets to achieve, competitors to overcome, or role models to use for inspiration.
Google's vision statement is "to organize the world's information and make it universally accessible and useful."