Set statements are used to set values for individual attributes.
Moves are used to move values into another matching view.
Analyze any Coolgen Program, you'll get to know the difference.
I assume you know what is an attribute and what are views.
For those who do not,
Views are like the variables in any other programming language. Each view contains one or more attributes.
View is more like having a 01 level base record and attributes are its subbordinates.