PLACING VIA

 

Vias are really tiny drill holes that are filled with copper. We use them mid-route to move a trace from one side of the board to the other.

To place a via mid-route, first left-click in the black ether between pins to “glue” your trace down. Then you can either change the layer manually in the options bar up top, or click your middle mouse button to swap sides. And continue routing to your destination. EAGLE will automatically add a via for you.