Avoids and closures are created in ContentTools in order to influence the roads selected when CoPilot, PC*Miler, and other Trimble Maps applications calculate a route. 

They have the same impact on route calculations. The difference is:

• Avoids are grouped in sets, and you can choose which sets are applied when calculating a route. In PC*Miler Web, for example, sets can be selected in Route Options. In CoPilot, they can be applied to select groups of vehicles or drivers via Account Manager.
• Closures are applied to all routes in Maps applications that are associated with your ContentTools account.