New instance of Websphere or create a new profile

I have an existant websphere portal installation , and i have been thinking about adding new one but i read that creating a new profile in this existant installation can be a solution so i have some doubts:

What's the differences between create a new instance of Websphere portal and create a new profile?

Solution

When you create a new instance of WebSphere Portal you are performing a new installation of WebSphere Portal entirely with new binaries and everything.
A new profile will reuse the application binaries. This also means you can't upgrade/patch one profile without the other.

Both installation methods will allow you to have separate servers and ports they listen to. Applications can be deployed individually.