Why do our computers store so many random images?

[Maplesyrupz]

I'm not sure if this is the right thread for this or not but i was rather curious! After running a Recuva deep scan I was looking through all the images. So many of them are just random images I've clicked on, item tooltips from games, or even thumbnails/screencaps from streams on twitch it seems. Why do our computers do this? I am very curious.

[Winapp2.ini]

Seeing images from the internet is called a cached image, cached images are cached so they needn't be redownloaded (just read from the hard drive which is much faster usually)

[Maplesyrupz]

Ah thank you! I just find it interesting so many images are cached, even things like the hearthstone disconnect screen. It makes sense though really! Thanks a lot, when people are coding things do they designate certain images to be cached on the hardrive? I noticed for some reason twitch.tv adds/their thumbnails for individual streamers are cached images which seems odd to me!

[TheWebAtom]

when people are coding things do they designate certain images to be cached on the hardrive

 

 

They can, but it's extremely uncommon. Usually web browsers cache every image you view while browsing the web. Each of these images comes with a "expires" header, which tells the computer how long it should hold onto the file.

 

The "expires" header is usually determined by the software running on the website's server. Depending on the server software, the default "time until deletion" can be anywhere from a few hours to a few months.

 

Some developers may wish to tell your browser to hold onto the file for longer than usual. This is achieved using what's called an "ExpiresDefault directive." This allows developers to specify things like 'ExpiresDefault "access plus 5 years",' which will preserve the file for five years after the day of first access. Most well designed web browsers are smart enough to ignore such egregious requests.

 

Since there is a constant churn of old cache files being deleted and new ones being downloaded, you can expect to find thousands of them hidden away when you run Recuva.

 

Edit: I noticed you mentioned tooltip image icons and other non-web graphics appearing. I'm not familiar with how (or if) the operating system caches these. I know applications written on Microsoft's .NET Framework can manipulate the Global Assembly Cache, which could theoretically be used to store a DLL file packed with bitmaps for later retrieval; but it doesn't sound like something a sane developer would do.