The Delay effect creates an echo using a copy of the original signal which is played with a delay.  
The following sliders are available in the Delay area:
Delay Time

Specifies the delay in playing back the copied signal.

Feedback

Specifies how many copies of the original signal are to be made.

The following sliders are available in the Mix area:
Dry Signal

Mixes the original signal with the copied signal, indicating the intensity of the original signal.

Effect

Mixes the original signal with the copied signal, indicating the intensity of the copied signal.

 


Delay