I'm confuse about web hosting

It is unlimited but as soon as your account becomes inactive for a certain span of time, the webmaster might delete your files cuz their space is not really limited. They just claim that to get a lot of subscribers. They need space for new users so they do something about it.

The "unlimited" storage capacity is impossible. It always has a practical limit, related to the server hardware. But it really depends on how much you want to store on it. If talking about videos, it can get quite large, but are we talking about 40GB or 10TB? For, say, 40GB it's manageable by most hostings, but the 10TB videos could be hard to store, in any case you should ask them detailed questions about that, and with an reasonably aproximated number to tell them. Also, you might want to move some of your videos to some paid storage site, such as Fileserve or Megaupload, as they pays you for their download in adition of storing them, which aleviates the load on the web server bandwidth too.

I've had sites on hosts that say unlimited storage. so far i haven't had any problems storing anything. i think it depends on the host though.