You can use Snap to maximize a window, which makes it easier to focus on that window because of less distraction from other open windows.
Drag the title bar of the window to the top of the screen. The window's outline expands to fill the screen.
Release the window to expand it to fill the entire desktop.
To return the window to its original size, drag the title bar of the window away from the top of the screen.
If you use multiple monitors, you can drag a maximized window from one monitor to the other.
Other ways to maximize an open window:
Double-click the top of an open window just below the top edge. To restore a maximized window to its original size, double-click the top of the window again.
On the taskbar, press Shift and right-click a taskbar button or a preview of an open window, and then click Maximize.
Snap might not work on some programs that have custom window behaviors.