Edgers have a blade that cuts into the ground next to harder surfaces. The main part of the edger usually has wheels that you keep on the harder surface. Be aware that grass and dirt fly as this is used. Wear safety glasses and cover your skin as fly...
I would stay away from the multi attachments. More things to go wrong or misplace. With a trimmer you can have either a curved shaft or a straight shaft. I find that the straight shaft is better for me as I have a large yard also. I own an Echo that ...
This is refered to as Jim Edger Panther Creek State Park west of Petersburg and was named after the Govenor Jim Edger.