When a builder describes a MOC as 8-wide or 4-wide it refers to the number of studs across the creation is. The term is most often used to describe trains or cars, but it can be used as a description for almost anything and is another way of expressing scale.
The following are common meanings for specific numbers.
- 2-wide: microscale trains
- 4-wide: the width of cars in sets for many years and considered a defining characteristic of the classic town scale.
- 6-wide: when used for trains this is also known a L-Gauge.
- 6-wide: when speaking of town or other modern themes this usually refers to cars and other motor vehicles and in the early 21st century was adopted as something of a standard in minifig scale sets starting with 4728 from the Harry Potter line.