The concept of numerical range of an operator on Banach and Hilbert spaces treated by several researchers. There are various manner to determine the last concept of closed linear operators in a Hilbert space. Among them we are interested of the numerical range of a closed linear operator which is the range of the restriction to the unit sphere of the quadratic form associated with it. This is a convex subset of the complex plane whose closure contains its spectrum. In this chapter, we present the new idea of the numerical range of two linear relations on Hilbert spaces. After that, we examines the aspects of the coupled numerical range for a linear relation and a linear operator on Hilbert spaces. Besides, we study its properties. After that, we establish some results describing the relationship between the various concepts of spectral theory and the numerical range.