PWM (Pulse Width Modulation) signal is a digital signal where you can achieve dimming by altering a square wave form.
This square wave form can be viewed as a pulse and changing the width of this pulse increases or decreases the dimming signal percentage that will be applied to your device.
Example of devices that can be dimmed with PWM signals are: Meanwell ELN Series -P drivers, Meanwell LPF Series drivers, Steve's LED drivers, LuxDrive FlexBlock drivers, LuxDrive BuckBlock drivers, PWM controllable Fans and Jebao controllable pumps.
Analog signal is one of the oldest type of electronic signals. It has been around for decades and can easily be achieved with a simple potentiometer.
The dimming signal percentage is increased or decreased as the voltage on the analog signal increases or decreases.
Example of devices that can be dimmed with Analog signals are: Meanwell ELN Series -D drivers, Meanwell LPF Series drivers, Inventronics drivers, Kessil LED fixtures, BuildMyLED fixtures, Apollo LED fixtures, JBJ LED fixtures, Jebao/SpeedWave controllable pumps and Tunze controllable pumps.