When applied to overlapping paths these tools in the Path menu allow you to perform boolean operations - the process of creating new shapes by combining two or more shapes.
Certain operations in this video reference the stack order of paths. If you are not familiar with the stack order of paths. please check out Part One of my Arrange Menu videos.
Understanding Compound Paths: https://youtu.be/zANZu2q_vv8
Arrange Menu stack order: https://youtu.be/hDgPKqOtP4k
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