Traffic director is a way to optimize and manage the traffic going to your domain by using geographical-based routing. Like this, your clients from Asia will get connected to your Asian servers; your European clients will connect to the closest servers they have in Europe and so on.
Traffic Director is a cloud-based implementation of Load Balancing (you can check our article on Load Balancing). It helps to improve the performance of your network. It can be incredibly useful for medium and large companies that need to deliver content to different parts of the world.
Some companies call this service traffic director, others global traffic director or GeoDNS director, but it is best known as GeoDNS, and that is why we use this term as the name of our service.