What it means in plain language
Inventory is the raw material of revenue management. Out-of-order rooms, OTA allocations, group blocks, and unsold inventory all count differently. The most expensive mistake is closing inventory by room type when you should be closing by channel - losing direct bookings because you blocked OTA inventory.
How Inventory fits in the bigger picture
Inventory doesn't live alone - it sits inside the Operations & Roles category and connects to 3 closely related concepts most working revenue managers track in the same breath. Pair this definition with the related terms below to build a working mental model - definitions in isolation are easy to memorize and easy to misuse.
Related terms you should also know
Each of these is one click away - start with whichever you don't already use daily: