The MoSCoW method is a simple yet effective tool that helps project teams to decide and arrive at a consensus while discussing various things like customer needs, stakeholder requirements, product/service development, etc.
It provides a structured approach to deciding the Must have (Basic needs), Shoud have (not basic but add significant value), Could have(Nice to have things), and Won't have (things that add no value or may even do damage).
Let us take an example of manufacturing a new model of car.
It might be easy to decide on a few things/features as to what the car should have but at the same time it can also be overwhelming to decide on a few factors that need to be different from the competitors. Here, if the project team uses the MoSCoW method,
M (Must Haves) - Basic needs like seats, brakes, gear box, mirrors, ABS, etc.
S (Should Haves) - Hybrid functionality of engine, Auto transmission, etc.
C (Could Haves) - Sensor-enabled locking system, roof-opening, parking assistance, etc.
W (Won't Haves) - Very low ground clearance, Speed capacity beyond 250 mph, etc.
The MoSCoW is a method very similar to the KANO model of analyzing customer needs and classifying them as basic (musts), wants(desired), and exciters.