Is Hilo its own island?

I'm curious to understand the geographical context of Hilo. Could you please clarify if Hilo is, in fact, its own island, or is it part of a larger landmass? My understanding is that Hawaii is made up of several islands, so I'm wondering if Hilo occupies a unique status in this archipelago. I'm looking for a definitive answer to help me better visualize the geography of this fascinating destination.