If you already have an ipad2 or higher, ipod touch (version 5 or above) or iphone 4s or above then you can update to the latest IOS 8. Just be aware after you update you will be prompted whether or not you want ot convert to apple drive and you will want to choose NO to this. The Apple Drive is to replace the icloud but only if all of your devices are going to be using IOS 8. Therefore if you have any older devices you will want to choose NO to upgrading to Apple Drive.
Next you will find the term "Camera Roll" is now gone.. So where do you find your photos? This link to the Apple Insider explains it all.
Of course you can learn all about the latest IOS 8 from the Apple website here.
Just be sure if you are planning on upgrading, to plug your device in to your computer and do it through itunes, making sure you have first BACKED UP your device (including apps) before performing the update. Although some devices may allow you to update directly from the device itself (if you have enough room left) I highly recommend plugging it in through your computer so that you have the backup. Otherwise you may find yourself resetting it to factory settings, losing everything you have already on the device!