Basically it's a "private cloud" (I hate myself for writing that) with which you can upload your photos, videos, songs, etc - so they live on/your/ server.
I've also seen it encouraged as something that someone provides for a few of their friends as well as themselves since, they argued, that it cannot be expected that everyone run their own server: at least not overnight.
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Even the Weather Channel has copied this Office 2013 style.
Basically it's a "private cloud" (I hate myself for writing that) with which you can upload your photos, videos, songs, etc - so they live on /your/ server.
I've also seen it encouraged as something that someone provides for a few of their friends as well as themselves since, they argued, that it cannot be expected that everyone run their own server: at least not overnight.