In linear algebra, the standard basis for an n-dimensional vector space is the basis obtained by taking the n basis vectors
where ej is the vector with a 1 in the jth coordinate and 0 elsewhere. In many senses, it is the "obvious" basis.
Standard basis are perfectly localized in the sense that all but one element of each base are zero.
There is a standard basis also for the ring of polynomials in n indeterminates over a field, namely the monomials. The existence of other 'standard' bases has become a topic of interest in algebraic geometry, beginning with work of Hodge from 1943 on Grassmannians. It is now a part of representation theory called standard monomial theory. The idea of standard basis in the universal enveloping algebra of a Lie algebra is established by the Poincaré-Birkhoff-Witt theorem.