Historically, hops added within 30 minutes to the end of the boil are generally considered to be the "flavouring hops" for non-whirlpool and dry hop styles. 

However, for whirlpool and dry-hopped beer styles like pale ale, IPA, etc, flavour hops are the whirlpool and dry hop additions as the flavours and types of hops used at these points contribute more strongly to the flavour than any hops added during the boil in these styles.