What is the purpose of Presser foot pressure?

The Presser foot pressure helps to feed the fabric evenly. I.e. heavier fabrics need more pressure (bigger number); delicate, especially softer fabrics like jersey need less pressure (smaller number).With the use of Presser feet with the Hopper mechanism (i.e. embroidery presser foot, BSR) a change of the Presser foot pressure does not bring any change of the fabric feed, as the moving of the fabric is done manually.The changes of the Presser foot pressure can be saved in the Personal Program.