Static Content is what iRiS GXP uses to display text across all it's connected apps, as well as providing the capability for Multi-language support.
Generally speaking any text within one of the iRiS Guest apps can be customised to fit your use case, branding or tone of voice, but there are some differences depending on the type text that you want to change.
For example on the Outlet Page below all of the highlighted areas are examples of Static Content. Static content is usually fixed text such as labels, buttons or links, and is applied at a property level.
And below in the second example in the same Outlet Page are examples of other content such as the name of the outlet or the descriptions on the items which can come from a POS sync or directly entered within iRiS GXP.