Swales are ditches dug on contour with the removed dirt placed on the downside slope of the ditch to form a berm. Water will get caught in the ditch and slowly soak into the ground. All sorts of plants can be planted on/in the berm to help hold the soil together and to benefit from excess moisture.
I wasn’t sure if I wanted to include more swales into the landscape as I wasn’t sure how well they would work with my soil. So far it looks like a success. Time to start mapping out my other swales.