Portals are a light weight separate web page that allows users from all over the world to connect annonymously or using all one single user to a more complicated system. Portals can have their own database or function just like an information gateway.
Do you have a system that you can't change but still you need to enhance it's functionality? An enhanced portal is probably what you need, as it allows you to connect to your system with the same user name and password but can be injected with the new functionality you so desire.
Do you need to let guest or anonymous users to connect to a system that requires logon? No problem, you just need a generic user that all guests can use and with a lightweight web application all your user community can login without the head aches of loging in and they can only see what you want. Another good thing is that you don't touch the original system at all.
Do you have data sent between 2 systems that you need to monitor? We can create a portal that monitors data transmission between the systems and generates graphs and statistics to ease data analysis. Also this kind of portal can alter and retrigger faild transmitted data