ℹ️ These tools are available to all users.
The Extrude and Offset Face tools are alike, but not the same.
You can use the Extrude tool to create a 3D body from a 2D sketch profile or linearly extend a face on a body. The extrusion does not affect any other face of the body.
Unlike the Extrude tool, the Offset Face tool cannot be used to create a body from a closed sketch. You use this tool to offset faces of a body. Basically, you're moving the selected face to a different plane and altering the adjacent faces—so, the body is extended and morphed according to that new position.
Take a look: