PLM cache specifically refers to offline image caching. It enables PLM to access file cover and preview images (via F1/F2 or the right-click menu on file records) even in offline mode.
PLM's cache files are located in the "cache" subfolder within the installation directory. You can manage them using "Cached files" under the "Data" menu: view/modify/delete/batch delete/inventory (remove unreferenced files)/compress images. (Cached Files)
You can delete all cached files by using "Clear Data" under the "Data" menu and then selecting "Clear all cached files". However, PLM will automatically cache files when viewing/editing online file data.
Runtime cache refers to temporary caches generated by PLM during each run, such as script buffering, to improve execution speed. If a script is manually modified, but PLM's behavior regarding the script doesn't change accordingly, you must exit PLM or manually click "Clear Runtime Cache" under the "Functions" menu to reset it.