The Toolbar consists of seven basic controls. Each relate to different parts of the Editor.
Transform Tools – used with the Scene View
Transform Gizmo Toggles – affect the Scene View display
Play/Pause/Step Buttons – used with the Game View
Cloud Button - opens the Unity Services Window.
Account Drop-down - used to access your Unity Account.
Layers Drop-down – controls which objects are displayed in Scene View
Layout Drop-down – controls arrangement of all Views