The connection among various schemes of renormalization is discussed, using a two-dimensional four-Fermi model as a laboratory. It turns out that definitions of the coupling, which are natural in a non-perturbative calculation, are connected singularly to definitions in perturbation theory. This has consequences in discussing asymptotic behavior at large momenta via expanding in effective coupling. Different non-perturbative schemes discussed in the literature are also singularly connected. This explains the appearance of a fixed point in one scheme.