Metadata Cache File

I'm stumped. I am trying to find a brush and did a search in all my computers' drives and attachments, and found the "brush" I wanted - yet it's labeled as a "Adobe Photoshop file browser medadata cache file"... when I double click it launches to Photoshop, but nothing is there.

So, what is a metadata catche file? I read on the web it's to identify parts of a picture, but all I am looking for is a little heart brush I used in an old pic! Can one use these files, or is it taking up space? I'm slightly confused, and hate being so!

Thanks for any insight!