The difference between Structs and Classes isn't about data vs. code: it's about what happens when you move the data around. And sometimes you want a Struct, not a Class.

Learn how to choose between classes, structs, and record types in C# for power, flexibility, efficiency, and performance.

a component is a slightly more complicated class, though I would guess that the inheritence bits take care of the complication for you, basicly its a class that does stuff in the background.