State
also: app state, application state, ui state
The information your app is holding and remembering right now, like what's in the cart, who's signed in, or which tab is open.
The data that describes a system at a moment in time and can change: UI state (a menu is open), session state (who is logged in), server state (records in the database). Bugs often come from state that is out of date, duplicated, or changed unexpectedly.
A board game in progress: where every piece is, whose turn it is, the score. Pause and write that down, and you've captured the game's state.
Many confusing bugs are state bugs: the page shows old data, the cart empties on refresh, a filter resets. Knowing the word helps you describe them clearly to your agent.
The bug is stale state: the cart count is read once when the page loads and never updated after you add an item.
The selected filters reset when I go back to the list. Where is that state stored, and can it survive going back and forth between pages?
Thinking state only means data in the database. State also lives in the browser, in memory, in the URL and in cookies, and those copies can disagree.