Skynet Web Portals consist of all the components needed to operate a publically accessible portal allowing access to the full Skynet ecosystem.
The web portal consists of:
a full Sia node
a full Handshake node
a web-app frontend
various scripts for server maintenance
This list will continue to grow as we add functionality to support things like accounts and payment processing.
We're planning on making web portals easier to deploy and operate for technical users. We'd advise against deploying a public web portal yourself unless you have sufficient dev-ops experience and knowledge of local laws and regulations. Most users should access Skynet through a public portal like Siasky.net.
We've started making resources available in the Developer Documentation for Running a Webportal. This is incomplete, but it can give you a sense of what running a web portal will look like very soon.