Sub domain issue

I am new to web hosting, never done it before. I am working on my assignment for uni. and wanted to know if I can create multiple subdomains when I am hosted with a webhost.

I want to be able to do the following: 1. users can sign up and get a subdomain of their choice. 2. users are allocated a limited webspace 3. The access to file types need to be controlled. In the sense that users can only upload/download certain file types like html, htm, jpg, gif, zip etc. 4. Users can have forms that work only within their subdomain. 开发者_开发问答for example the domain name is www.example.com the user signs up for [mysite.example.com...] where "mysite" is the subdomain.

You're talking about several different things here. Firstly to enable a user to define an account with their own subdomain would best be tackled by using a wildcard DNS entry for your domain. Whether your hosting company offer or allow that should be your first question.

Once you have that setup then pretty much everything else you want to do can be controlled by the application you build.