Why is all this stored on my nexus/

[little duck]

When looking through the task manager and opening android--data--com.firestudio--files, I find literally hundreds of icons labelled Panel A1 up to Panel F99, these are all film stills.
Then I get to A number of icons marked Shared Movies, these will not open.
Next comes Thumb nail User Online which are more film stills, then User Online which seem to be portrait photos some captioned "wire image", and finally YTHotNewly which are more film stills.
Where did they come from, and should I delete them as they must be using a lot of space. 

[S.Prime]

I am assuming that you mean file manager instead of task manager and that you have Music Tube by Firestudio installed. If I am correct you can go to Settings - Apps - Music Tube and select clear file and data and you should see the files erased. If you are concerned about the size of the folder named "files" long press on the "file" folder in any file manager and tap properties and you will see the size of the folder.

[little duck]

Thanks for that, it good to know that I can delete them en bloc, but could you help me understand why they are there, what purpose do they serve?

[JayJ]

I don't use this application but I would imagine these are an image cache, lots if apps use a cache as it helps the OS find things quicker. Most of these are very small in size shouldn't take up too much space overall on your internal storage.

Sent from my AOKP Nexus 4 using Tapatalk 2©

[S.Prime]

Information in sent through the internet in packets or bundles and then it is assembled by your computer, tablet, phone, etc., to provide video and/or audio. Your device's playback application will buffer these packets so as to provide smooth play. If your video or audio pauses, then the buffer has been depleted and your application is waiting for the buffer to replenish. The files you are seeing are the buffer and the application will manage the buffer as is required, if the app is functioning correctly.