I have created a SharePoint provider-hosted App from Visual Studio 2012 template. And now I want to move my Host Web to existing ASP.Net web site. What steps should I do to migrate VS template for host web to a real ASP.Net web site?
Actually, you would need to create what is either a Provider hoster (e.g. handle hosting for your ASP.NET Web Site) or "Auto-hosted" SharePoint App (automatically deployed to Azure - new or existing Web).
The major difference is that SharePoint hosted, practically means having the HOST Web, surfacing information from an automatically created sub-site in the called the App-Web, which usually is location in a dynamically created site collection, according to the domain you configured in the SharePoint App Management service.