In most online games, it's usually more beneficial for a player to create one single character and focus most of his or her game time on that one character. Sometimes long time players may want to create new players without having to delete their main character, and fortunately Tom Clancy's The Division will allow this.
In fact, it has been recently announced that players of The Division will have four slots to use for character creation. Each of the four slots can be progressed as standalone characters, apart from each other.
Interestingly, players will be able to switch out the characters they use straight from the start menu. This means that if you're about to head out on a mission that may require a certain build or load out, you'll be able to switch to a more suited character you may have made in the past. This is something that isn't seen often in online games so it will definitely be very interesting to see exactly how The Division manage to pull this off.
One reason players may want to create multiple characters in The Division is that characters can only use two skills at a time. Fortunately, Ubisoft has revealed that you can switch out those skills so you don't have to create more characters to make use of other skills. Players will even be able to switch out the skills they use in the middle of a mission, so players will not need to create a new character just for this purpose.