Walter would tell us that the suburban part of Long Island - Nassau and Suffolk Counties - is divided into 13 Towns (called Townships in other states) and 2 small cities. The Towns are further divided into Villages and Hamlets.
Islip is one of those 13 towns. And within Islip, there are hamlets called West Islip, East Islip, Central Islip, Islip Terrace and Islip (Islip Manor). These are large areas, widely spread apart and completely different from each other.
If you are reading about something happening in Islip, you need to be able to tell the difference between the Town of Islip (which is over 100 square miles of land) with Islip Hamlet (Islip Manor) which is like a neighborhood or local community.
https://en.wikipedia.org/wiki/Islip,_New_York (Town of Islip)
https://en.wikipedia.org/wiki/Islip_(hamlet),_New_York (Hamlet of Islip which is inside the Town of Islip)