longest match rule
if i wanna try to search your name
i will type m & ot wills how all names start with m
then i type ma then iw ill show name starts wil ma
so it goes & finally i will type marco and it will show name with marco.
so it will not show other m name which does not have arco after . so longest match.
same happens with destination network address matching of a packet with network address of routes in routing table.