Each competitor is required to carry a control/punch card. The card has to be presented at the Start line and handed in at the Finish line, whether or not the competitor decides decides to complete the course. The control card is marked by needles or electronically at each control point to show that the competitor has completed the course correctly. All controls need to be punched in the order they are shown on the map. Most events now use electronic punching, although cards and needle punches are still widely used.
Electronic punching is a faster, better way to record your visit to each control on an orienteering course. Instead of carrying a paper card and punching it at each control location, you wear a platic e-card, or 'finger stick', which contains a microchip. At each control site, you insert the finger stick into a control unit, which records the controls number and time onto the microchip.
Once the course is completed, the data is downloaded at the transfer station, and the contestant receives an instant printout of the time and splits. Even better, compiled printouts can be seen. These show everyones's splits for the course, helping each competitor see where time was gained or lost.
Make your own decisions, do not follow others.