How sweep works in AutoCAD?
What is sweep?
It is a tool in AutoCAD and in many other 3D software which makes some shape follow its path you drew,now this is not gonna help you if I do not show you how it works :)
You can see here on the picture,the pentagon is the shape and spline is the path pentagon will follow it down its length.
I activated the Sweep tool and I need to select object to sweep.
Now I need to select the path which is the spline.
And this is what we get and no matter where the position of my pentagon is regards to spline the result is the same,It always follows your path.
Lets return now to see some options with sweep like Aligment.
Now if you click Aligment it will ask you if you want your object to be perpendicular to path or not,I will show you with pictures what I mean.
This is the case when it is perpendicular to its path,look at the ends.
This is the case when it is not perpendicular and it just follows the spline.
Now I am going to show you the Twist option.What this tool does is twists your shape around your path with a specific angle you write.
I wrote 360° and this is the result.