The Line panel is located at Geometry > Create > Line and it allows you to create lines using a wide variety of methods. Click on the various subpanels below (icons at the top of the panel) to get a description of their function.
The Line Edit panel is located at Geometry > Edit > Lines and allows you to edit the lines using various methods. Click on the subpanels below (listed on the left side of the panel) to get a description of their function.