Shunting, in railway operations, involves the process of sorting items of rolling stock into complete train sets or consists. The United States terminology is "switching".
The occupation of shunter is particularly dangerous as there is a risk of being run over and on some rail systems, the shunters had to get between the wagons/carriages to complete the coupling process, especially where hook-and-chain coupling systems are in use. This was particularly so in the past (e.g. the Midland Railway used to have an ambulance wagon used at Toton Yard for injured shunters). In the past the main tool was a shunting pole, which allowed the shunter to reach between wagons to fasten couplings, without having to physically go between the vehicles.