Inner products are mathematical operations that provide a measure of the similarity between two vectors within a vector space. Synonyms for inner products include scalar products, dot products, and matrix products. Scalar products refer to the multiplication of two vectors to produce a scalar value. Dot products are another way of describing scalar products and derive their name from the dot operator used to denote the operation. Matrix products are a way of representing a collection of inner products between two sets of vectors, where the product is determined by the entries of the matrices. In mathematical discourse, these terms may be used interchangeably to describe the same operation.