Simplify the following text for a Grade 4 native English-speaking person.
Original: The dimension of a vector space is the number of vectors in any basis for the space , i.e. the number of coordinates necessary to specify any vector . This notion of dimension ( the cardinality of a basis ) is often referred to as the Hamel dimension or algebraic dimension to distinguish it from other notions of dimension .
Simplified: There is one number for each dimension .