Personalising your character is what separates each character of the same class apart. If you have played Diablo 2 before, you'll be more than familiar with the idea of a skill tree and Blizzard has employed a similar system for the game's Talent point assignment.
As you play the game and your character levels up, at each level beyond level 10 (inclusive of level 10), the player is given one talent point (TP) to assign to their Talent trees. Each character class has three different trees categorised into the different types of skills/spells they have at their disposal.
How do Talents work?
With the maximum character level set at 60, a player can effectively assign a maximum of 51 Talent points to their tree (levelling from 10 to 60 inclusive of level 10 gives 51 TPs). Attaining a certain Talent's ability to augment your character is not as simple as just assigning 1 single point into a Talent. There are prerequisites for all higher than tier 1. For example, to activate and utilise a Talent in the second tier of the tree, you may have to assign 5 of your Talent points into a talent in the top tier prerequisite before it becomes active. Because the system is tiered, players have to think long and hard before assigning a point. Once you have allocated a talent point, you cannot unallocate it, unless you go to your class trainer and unlearn all your talents, for a fee of course.
While planning, take note that the "ultimate talent" in each of the talent trees require 30 TPs to be already placed in that tree. This means that to learn the ultimate talent, you need to place at least 31 points in that tree, and this prevents you from learning the ultimate talent of the other 2 trees because you only have a maximum of 51 TPs to use.
Each character class features three different talent trees and they are all different for each class. You may want to specialise in one tree or spread your points out over 3 trees. Spreading your points will mean it would be impossible for you to become efficient in one single Talent discipline. The choice is yours.
What if I choose the Wrong Talents?
Don't panic! Players have the ability to unlearn all their talents and start over. In the game players can reset all their talent points by visiting their class trainer. However, this costs gold and each time you do it, the more expensive it will become. The first talent reset will cost 1 gold, the second 5 gold, the third 10 gold. Each subsequent talent reset will cost 5 gold more than the previous until the cap of 50g is reached. Keep in mind that all points are removed from all trees when resetting your talents. As a result of this you will also lose all spells, skills and abilities gained from having those talents. Should you reacquire the talent again, you will be required to buy that spell and all subsequent ranks of that spell again from your class trainers.