rerendered

Rerendered is the past participle and, less commonly, an adjective referring to something that has undergone rendering again. In computing, rendering means converting data into a visual or structural output, such as pixels on a screen, HTML, or a structured scene. Rerendering occurs when input data or state changes require updating this output.

In client-side UI frameworks, components may be rerendered in response to changes in state, properties, or events. For example, in React a component rerenders whenever its state or props change; a virtual DOM comparison determines which parts of the real DOM must be updated. Frameworks differ in when and how rerenders are triggered and how expensive they are, influencing performance considerations and update strategies.

In server-rendered applications with client hydration, the initial HTML is rendered on the server; the client then rerenders certain parts during hydration or subsequent interactions, and may rerender again if data changes. Rerendering also occurs in rendering pipelines, such as game or visualization engines, where frames are redrawn due to camera movement or scene updates, effectively producing updated output.

Performance considerations are central to rerendering: unnecessary rerenders can degrade responsiveness. Common optimization techniques include memoization, avoiding unnecessary state changes, using immutable data structures, and selective update strategies (for example, memoization of components, shouldComponentUpdate in some frameworks, or similar mechanisms in other libraries). Understanding when and why rerenders occur helps diagnose rendering behavior and improve runtime efficiency.