Photography has changed drastically with digital cameras you can shoot many pictures and store them for later use. With this in mind, some choose to leave their photos on their camera. We DO NOT recommend this practice for storage. The main reason is that you may need the SPACE quickly one day and possibly run out of valuable space. It happened to me when the roof of the building next to mine caught on fire and I had a camera (believe it or not) and could only capture 4 shots because the card was full of photos that should have been deleted earlier. You can also increase the speed of your computer by keeping the folders free from tons of data.
Here is what we do recommend for storage/backing up your photos. First, I copy the photos from the camera onto my computer for editing without deleting them. I edit, tweak and then copy the edits and photos onto my back up drive. I check the back up files by opening and scrolling through the thumbnails making sure they open. I then DELETE the photos off of my computer and camera.
Every quarter, I back up my back up. You really should back up ALL of your files (not just photos) on your computer at least quarterly. There are digital services like (www.sugarsync.com) or cloud services that backup data for you automatically according to a schedule you create. I use hard drives to protect my digital creations and the back up drive is stored in a fire-proof box (just in case).
For my hardware back up I have two devices. My smaller (more portable) hard drive is a SEAGATE brand. http://www.seagate.com/external-hard-drives/portable-hard-drives/standard/backup-plus/ It has 500 gig which store thousands of MP3's, documents, graphics, templates, videos and of course PHOTOS both scanned and taken digitally.
My larger drive is a 2 TERAbyte Western Digital. It is super heavy so it would not transport well like the smaller Seagate. This is the drive I use to for my quarterly back ups.
So, go to your calendar app and schedule a backup time for each quarter for the rest of the year unless you subscribe to an auto service and back it up!! :)