Practical electronics · prototyping
Each column of five holes (a–e, or f–j) sits on one metal strip, so anything in those five holes is joined. The gap down the middle separates a–e from f–j. The long + and − rails run along the edges, and the top rails are not joined to the bottom rails. Hover over any hole to see what it connects to.
Shortcuts: R rotate the selected part (also while dragging), Delete remove it. Drag a part back onto the tray to bin it.