HEBREWS | It is clear from the use of the term 'Hebrew' in 1 Samuel that the author does not see it as exactly interchangeable with 'Israelite.' In the main, this is an ethnic designator used by foreigners - the Philistines - to refer to the Israelites. The Philistines consider the Israelites to be Hebrews. However, there are others Hebrews who are not exactly identifiable as Israelites, and it is not clear that the Israelites think of themselves as Hebrews.
ETHNOGENESIS | It is worth noting that this memory recalls the period before the establishment of the Hebrew kingdoms, and - as Israel Finkelstein suggests - 'Israel' may not have been the settled identity of the various ethnic groups in the hill country. 'Hebrew,' then, may refer to a class of people rather than a self-identified ethnic group. Israel may have been a Hebrew group, but not all Hebrews considered themselves part of an emerging Israelite ethnic identity.
CONFLICT | Ethnic identities are largely a matter of self-ascription and can change. Conflict between groups has often proven to be a key motivator in the formation of ethnic identity and difference. 1 Samuel recalls a time probably in the second half of the eleventh century BCE when urban settlement was underway in the hill country. At this time the Palastu - the Philistines - had colonised and fortified the coastal plain. These 'Sea People,' an essentially foreign people in the Levant, put significant pressure on the Hebrew settlers and this may have stimulated the process of ethnogenesis. The demand of 'the people' for a king should be understood as part of this process.
SHIFTING ALLEGIANCES | Not all Hebrew understood themselves to be part of Israel, and the Israelites did not necessarily see all Hebrews to be part of the community of Israel. There may have been closer tribal, clan, cultic, and linguistic relations between the Hebrews and the Israelites than between the Hebrews and the Philistines, but this closeness may well have accentuated division. Not all Hebrews would have been content with Israel's growing power and influence over the hill country. Sometimes we get the impression Hebrews were a class of bandits and/or mercenaries.