If you ski straight down and move your body from side to side, your skis will be edges in relation to the slope. The skis dig into the snow and begin to turn. The action of angling the skis as we describe here is called edging.
The movement from side to side is therefore essential and extremely important to learn. Try this little exercise to understand the fundamentals behind edging: Stand up and lean one foot sideways towards the other foot. The foot is now angled in relation to the floor. We also say that the foot is edged against the surface. Now try to lean booth feet from side to side. Finally, try to lean your feet at the same time as you lean your body to the same side. This exercise shows what has to be done to edge your skis to begin the turn.
It is, of course, always easy in theory! Without a doubt, it feels harder when you have ski boots on and are on your way down a slope. Still, try to edge the skis enough to dig into the snow and this begin turning. Be careful not to force your skis into a diagonal position in order to make them turn. Have patience and, instead, tip the skis onto their edges so that they first dig into the surface of the snow, and then secondly form an arc that ends up in a turn. The skis will edge more or less depending on how much you lean into the turn, and how much you angle your ankles and knees. Be careful not to lean your upper body too much into the turn, especiall if you are skiing slowly. Instead use your ankles and knees primarily to tip the skis on to their edges.