This chapter is a brief treatment of the index notation and Cartesian tensors needed for the rest of the book. Sections 2.1, 2.2, 2.3, 2.4, and 2.5 are on rewriting the familiar vectors, matrices, determinants, scalar and vector fields using the index notation, summation convention and the comma convention for partial differentiation. Section 2.6 is on Cartesian tensors including basic tensor algebra and tensor calculus.