You can perform actions on groups of windows in addition to individual windows. Each window belongs to a group you can minimize, drag to a new location, float in a separate window, or dock back into the IDE window.
Minimize the Projects, Files, Classes, Classes, and Services windows in the top left by clicking the Minimize Window Group button on the right side of the group.
Right-click in the tab area of the group or choose Window > Configure Windows and select Maximize (Shift+Escape) to maximize the Window Group.
Note that you can choose other options such as Float or Dock your window group.