The cache stores thumbnail and metadata information (as well as metadata that can’t be stored in the file, such as labels and ratings) to improve performance when you view thumbnails or search for files. However, storing the cache takes up disk space. Purging the cache deletes cached metadata and thumbnails.
Select Automatically Export Caches To Folders When Possible to create a cache in the viewed folder if possible. For instance, it’s not possible to place the cache files in the viewed folder if that folder is on a burned CD. In that case, Bridge places the cache files in the centralized folder instead.
Click Choose to specify a new location for the cache.
Click Purge Cache to clear the entire cache, freeing room on the hard drive.