When you knit you can hold your yarn in either your right hand or your left hand. If you hold it with your left hand this style is frequently known as Continental style knitting or 'picking'.
When you hold you right hand, if you move your whole hand to work the stitch this is know as English Style or 'throwing'. However if you sit your needle in the 'crook' of your thumb and index finger (or with long needles tuck the tip under your arm) you can then just move the tip of your index finger up and down to create your stitches. This is also known as 'Flicking'.
See both Knitting Styles in action here: