In case you just upgraded your iOS powered device to iO7 or any other version and now this device runs slower than it used to, this resetting of the device procedure might speed things up.
Not only that you can share files — like documents, images, and PDFs — without having to email them as attachments. You can share the whole folder containing the documents.
If the DVDs, USB sticks, phones, cameras or any other media and devices are automatically starting to play or open explorer windows and your don't want them to, this is how you tweak the AutoPlay settings.
If you are getting a vast number of email notifications sent by your Twitter account and they started to annoy you, this is how you disable and manage them.
If you use a lot of different usernames and passwords it is difficult to remember all of them. KeePass is an interesting solution where all your passwords are kept in one safe place and protected with one password.