Read the dictionary definition of vast. All definitions for this word.
1. unusually great in size or amount or degree or especially extent or scope
1. huge government spending
2. huge country estates
3. huge popular demand for higher education
4. a huge wave
5. the Los Angeles aqueduct winds like an immense snake along the base of the mountains
6. immense numbers of birds
7. at vast (or immense) expense
8. the vast reaches of outer space
9. the vast accumulation of knowledge...which we call civilization