This linearization implies that the Lagrangian description and the Eulerian description are approximately the same as there is little difference in the material and spatial coordinates of a given material point in the continuum. Therefore, the material displacement gradient tensor components and the spatial displacement gradient tensor components are approximately equal. Thus we have E ≈ ≈ e ≈ ≈ ε ε = 1 2 ( ( ∇ ∇ u ) T + ∇ ∇ u ) or E K L ≈ ≈ e r s ≈ ≈ ε ε i j = 1 2 ( u i , j + u j , i ) where ε ε i j are the components of the infinitesimal strain tensor ε ε , also called Cauchy's strain tensor, linear strain tensor, or small strain tensor.