The Architecture segment provides a top down view of your Gateway. You can see your Ignition version and resource usage, as well as similar information with a redundant Gateway, if one is connected. You also get an overview of the Gateway Network including how many active connections there are, and what is the amount of data being transferred between them.
The Environment segment provides some basic information about your server such as the Operating System (OS), Java version, available disk space, and IP address of detected network interface cards (NIC)..
The Systems segment summarizes each of Ignition's systems. Here, you can see how many modules you have installed as well as how many Tags are configured in your Gateway, along with a handful of other information. Click on any of the links in blue to find out more information about a particular system.
The Connections segment shows all of the systems that Ignition is connected to. If any of these have issues, they will be outlined in red. Clicked on the connection to be taken to the relevant page within the Status tab.