The Windows 10 desktop operates the same as Windows XP, Vista and 7 (but not Windows 8). Traditional desktop apps and tablet-style apps can be displayed side by side, moved around and resized. However, if you work on a tablet, you can switch to Tablet mode and make all apps span the entire screen (maximized). In addition, the Start menu is full screen in Tablet mode, much like the Windows 8 Start screen. See
Win10 Tablet mode.