The first time a visitor goes to any Space page she’ll see an information box about what’s this Space about.
This is how the information box is shown to participants and visitors:
They can hide this box by clicking in the close button [X]. This gets remembered by the application. They can open this box again by clicking in [Help: ?].
As this is something that depends on your given installation, an administrator can customize these Help sections, adapting them to your needs.