Methods of combining objects
You can combine vector objects to create shapes in a variety of ways in Illustrator. The resulting paths or shapes differ depending on the method you use to combine the paths.
Pathfinder effects
Pathfinder effects let you combine multiple objects using one of ten interaction modes. Unlike compound shapes, you can’t edit the interactions between objects when you use a Pathfinder effect.
Compound shapes
Compound shapes let you combine multiple objects and specify how you want each object to interact with the other objects. Compound shapes are more versatile than compound paths because they provide four kinds of interactions: add, subtract, intersect, and exclude. In addition, the underlying objects are not changed, so you can select each object within a compound shape to edit it or change its interaction mode.
Compound paths
Compound paths let you use an object to cut a hole in another object. For example, you can create a doughnut shape from two nested circles. Once you create a compound path, the paths act as grouped objects. You can select and manipulate the objects separately using the Direct Selection tool or Group Selection tool; or you can select and edit the combined path.