A rolling shutter reads the sensor row by row. A global shutter reads every well at the same instant. That sounds like a brochure line. In the world it is the difference between a propeller that looks like a propeller, and a propeller that looks like a banana.
In one sentence. Rolling is cheaper and usually finer in still light. Global is what you buy when the world moves, or the lights blink.
What rolling actually does
The top of the frame happened a little before the bottom. On a slow scene you will never see it. On a passing train, a robot arm, a spinning fan, or a forklift crossing the dock, vertical lines lean. Circles become ovals. A barcode can shear enough to fail.
LED lighting adds a second trick. Many lamps PWM. Rolling readout samples different parts of the blink. You get bands. Global does not make bad lighting good, but it stops the bands from walking down the frame.
What global costs
Global shutter silicon is usually louder, more expensive, and lower in resolution for the same money. That is fine. You are paying to keep geometry honest. Do not buy it for a doorbell that looks at a still porch. Do buy it for a pick-and-place, a drone, or an AMR that turns in a bright hall.
How to read the library
The sensor library has a shutter filter. Use it as a hard split, not a nice-to-have. If the object moves by more than a pixel during the readout time, start on the global side. If someone says "we can correct rolling in software," ask them to correct a sheared Data Matrix at 2 m/s and then we can talk.