E: Entry-level, with fewer functions, cannot be upgraded and rotated, and only has a USB hub for 23 inches or above. P: Professional grade, can be lifted, lowered and rotated, has a USB device and a DVI interface to ensure a perfect screen. S: UltraSlim, ultra-thin panel home system monitor.

Hello, E is the most entry-level model. S is an ultra-thin model, which is more high-end than E. Now comes the P series, which is a more professional monitor model. The last is the U series model, which is based on the P series and uses a better panel.

S19A100N: S stands for Samsung, A is a green and healthy display, 19 represents the size, 100 represents classification mainly by appearance; the smaller the value, the configuration and price of this type of model are relatively high. The numerical model should be lower, and N represents the N series monitor.

It is the model of the machine, 503S represents its configuration, and the monitor E1909W also represents its model. The first two digits represent its size. You can find them online and buy them in stores. You can You can also call Dell customer service for consultation.