A sequence {xn} which converges to a limit l is said to have rate (or order) of convergence r ≤ 1 if there exists M such that
for sufficiently large n. For r = 1, it is further required that M ≤ 1. If r = 2, then the convergence is said to be quadratic. If r = 1 and
then the convergence is said to be superlinear, linear, or sublinear depending on whether m = 0, 0 < m < 1 or m = 1.