The menu bar

Every space is a cell, in the order yabai numbers them:
| Looks like | Means |
|---|---|
| A filled box with the name cut out | The focused space. |
| An outlined box | The space shown on another display. |
| Plain text | A space with windows. |
| Faint text | An empty space. |
| A dot at the top right | The space holds a stack (or uses yabai's stack layout). |
| A bar underneath | A window on the space wants attention. |
| A dashed box | A native fullscreen app. |
A space shows its label when it has one, its number otherwise. With more than one display, the displays are separated by a wider gap, or get an item each (One item per display in Settings).
Click a space to go there. That needs yabai's scripting addition; without it Yabar focuses one of the space's windows, which makes macOS switch to it (an empty space then can't be reached this way).
Right-click (or Control-click) the item:
- Label Space N…: name the focused space.
- Scratchpads: when yabai's scripting addition is loaded.
- Stack Indicators: the style and placement, at a glance.
- Settings… (⌘,), the version, Check for Updates…, Quit.
- Last, every space with its windows: pick one to go there. Stacked windows carry their place in the stack.