This chapter provides fundamental error bounds for kernel-based interpolation and introduces classical families of radial basis functions. We present stability analysis through conditioning of kernel matrices and derive pointwise error estimates involving the power function and fill distance. Key examples include infinitely smooth kernels (Gaussian, inverse multiquadrics), finitely smooth kernels (Matérn, Wendland functions), and conditionally positive definite functions (thin-plate splines, radial powers). For each family, we discuss native spaces, approximation orders, and stability properties.