Honor talent

Honor talents were special abilities that could be chosen to augment your character, specifically tailored for PvP. Honor talents could be passive bonuses or active abilities. Each specialization had its own selection, with 18 honor talents split over 6 tiers. Honor talents were limited by honor rank, with a new tier becoming available every other rank until rank 10, and every 3 ranks after that. Most honor talents were class-specific, and a majority of choices depended on specialization. Honor talents offered a further level of customization beyond class and specialization selection, and could be changed very easily and cheaply.

Honor talents' effects were inactive when not flagged for PvP, such as world PvP, battlegrounds and arenas.

Gaining honor talents
Talents were split over 6 tiers, with 3 honor talents on each. Each tier was unlocked when the character reached the appropriate rank:

Official preview
From Legion PvP Preview:
 * Honor Talents are a special set of Talents that are only active when a player is in a PvP instance (such as a Battleground or Arena) or otherwise engaged in PvP combat, and work in addition to your normal Talents. They are unlocked, one at a time, as your Honor Level increases. So, by Honor Level 10, you'll have one option available in each row, but as you continue to increase your Honor Level, more and more options will become available for you to change up how you approach PvP gameplay.
 * For example, a Windwalker Monk who has reached Honor Level 10 can choose Rushing Tiger Palm, which lets them use Tiger Palm at range to dash toward and slow their target. Or, a Restoration Druid who has reached Honor Level 46 can take Deep Roots, which makes their Entangling Roots spell no longer break when the target is damaged.
 * Which Honor Talents you choose can have significant impact on how you play your character, and allow you to tailor your abilities to fit with the type of PvP content you're participating in, or even who you're playing with!