skarojohn :
why_wolf :
That's what created it. https://helpx.adobe.com/photoshop/kb/optimize-photoshop-cc-performance.html
This is probably it! Thank you! Btw what should I do with the folder?
Judging by the name "cache", I would imagine that if the project is not something you'll be touching frequently in the near future, you can simply delete it. I only suggest avoiding that otherwise as you'd waste time rebuilding the cache otherwise.
But if the stuff it probably cached is no longer useful, neither is the cache, ergo, no need to keep it around for any of the speed enhancements it would otherwise have offered.