In the Basic Zone modes, to prevent spoiled shots, most functions are set automatically and cannot be changed. In the <d> (Program AE) mode, you can set various functions and be more creative.
In the <d> (Program AE) mode, the camera sets the shutter speed and aperture automatically to obtain the standard exposure.
The difference between the Basic Zone modes and <d> is explained on page 170.
*<d> stands for Program.
*AE stands for Auto Exposure.