Slots are dynamic placeholders that either wait for content (passive slots) or call for it via a renderer. A slot can contain a single type of content or multiple types. Using more than one type of content in a single slot can have unpredictable results if not configured correctly. Slots work in tandem with scenarios to deliver content on a page.
In aviation, an allocation of air-traffic management time or space at a congested airport: “Airlines bid for slots at each season, and the best value is often paid for early morning landings in the face of congestion.” From Old Low Dutch slotte, from Middle Low German slod; see also slit (def. 1).
The slot in the screwhead S holds the cylindrical end of the pin p, which is screwed into the slot in the type-wheel
A slot can also be a position in a group, series, or sequence, as in “the editor’s slot” or “his job at the Gazette.” From 1915; compare with berth (def. 2). Also, slit, notch, or gap, as in the narrow notch between the tips of the primary feathers in some birds that helps to maintain a continuous flow of air over the wings.