How do you get talents in World of Warcraft?

Previously, talent points were awarded starting at level 10, with additional points awarded at regular intervals (every other level).

With the launch of the Mists of Pandaria expansion, talents have been streamlined into a smaller set of choices, starting at level 15, and you are given a new tier and set of talents to choose from every 15 levels afterwards. Each tier offers 3 different talents, which vary between class. With this streamlining, many of the previous talent tree options were either made into passive abilities for each class or removed entirely.