The word slot is a noun and can refer to:
A slot is a dynamic placeholder that either waits for content (a passive slot) or calls out for it (an active slot). It has an identifier which determines the type of content it holds. In a Web application, it is used to manage the placement of content in a page. Slots work with renderers, which specify the way that content is displayed. The number of slots in a Web application can be limited, but the content in a slot cannot be changed once it is set up. A slot can be filled with content from a repository or through the use of a targeter, which allows it to hold different types of content. It is also possible to use a combination of both scenarios and targeters to fill a slot. It is not recommended to use multiple scenarios or targeters for the same slot, as this could result in unpredictable behavior.