Actually RapidShare is more of a service that temporarily allows you to host your big files on their server to allow users to share with other people who can then download the files. And the service is for free, with paid service for better features.
RapidShare allows you to upload files up to 100 MB in size, for unlimited number of files, regardless of file types, and with just 1 click! Users are allowed to download the files for unlimited times, although free uploads are limited to download of 30 MB per hour. Furthermore, all upload and download at full speed of the service, and that’s 16 Gbps Up and Down. The files will also be hosted on RapidShare as long as 30 days until last download activity.
Other limitations for the free uploaders are limit of 1 parallel download at any time, no support for download accelerators, no support for resuming broken downloads,
delays of tens of seconds before you can download immediately (some limitations of RapidShare for free user have been changed) and etc. If you go premium (fee-based) for a nominal sum, all these limits will be non-existence. And the uploaded files will be kept forever too (of course, at least until you ceased to be premium member)!
Update: Rapid Share has shutdown its service on 31 March 2015.