  We re-examine the physical relationship between Extreme-UltraViolet (EUV)
waves and type II radio bursts. It has been often thought that they are two
observational aspects of a single coronal shock wave. However, a lack of their
speed correlation hampers the understanding of their respective (or common)
natures in a single phenomenon. Knowing the uncertainties in identifying true
wave components from observations and measuring their speeds, we re-examine the
speeds of EUV waves reported in previous literature and compare these with type
II radio bursts and Coronal Mass Ejections (CMEs). This confirms the
inconsistency between the speeds of EUV waves and their associated type II
radio bursts. Second, CME speeds are found to have a better correlation with
type II radio bursts than EUV waves. Finally, there exists a tendency for type
II speeds and their range to be much greater than those of EUV waves. We
demonstrate that the speed inconsistency is in fact an intrinsic tendency and
elucidate the nature of a coronal shock wave consisting of both driven and
non-driven parts. This suggests that the speed inconsistency would remain even
if all other uncertainties were removed.
