A project holds everything in the Maps pane: your layers, their styling, and where the map sits. You work on one at a time.
Create or open a project
The creation steps are on Create a Project. To open an existing project, pick it from All maps on the Maps home, or from the project menu inside an open map. If nothing is active yet, the explorer shows "No active project"; a fresh project shows "No project layers yet" until you add a layer.
Create a separate project when the work has its own operational scope — its own layer stack, extent, and publishing target. Ava Reyes at Meridian Geospatial, for example, keeps the "Harbourview Network Buildout" project separate from unrelated regional work so its layers, versions, and releases move together.
The project menu
The project menu (the ⋯ at the top of the layer explorer) is where project-level actions live: "Add Layer" and "Add Layer Group" to build the layer tree, "Add Data File" to bring in a file, "Print Map" for a layout (Print and Map Layouts), "Publish to Server…" to publish it (Tamaat Server), and "Project Settings".
"Auto-hide Pane" collapses the layer list until you hover back over it, which buys you the whole width for the map.
If the layer tree fails to load, the explorer reports "Layers unavailable" — reopen the project or check your connection before retrying.