It looks like you have the 'Editing Plane' turned on.
You can find a toggle in the View menu.
Also in the Work Environment there is an option in the 'on screen options' section to display the editing plane only during editing operations.
Also in the 'grid & background' settings yo can control the colour and opacity of the grid.
Barry.
One of the forum moderators.
Versions 6.5 to 27
i7-10700 @ 2.9Ghz, 32GB ram, GeForce RTX 2060 (6GB), Windows 10
Lenovo Thinkpad - i7-1270P 2.20 GHz, 32GB RAM, Nvidia T550, Windows 11