For each resource URI, api indicates the service package, v1 indicates the service version, and the text after v1/ indicates URI templates. Because each resource URI contains a distinct URI template, each resource URI is mapped to a different service REST rule.
@Kavileswar I am speculating it to be a generic thing, which Pega internal functions may have added during url construction - when you save as. It's not necessary to have "api". Maybe you can raise a ticket with the product team for more info, as this is not the case in older versions.