1. Buffs & Debuffs
Most often, a buff refers to a temporary beneficial spell or effect placed on a player. Buffs can range in effect from simple personal shields to buffs which augment almost every category of stats a given player may have for their race or class. Every buff is located on the left side of your map and the debuffs are located on new line after the buffs.
Buffs can be of two types: those that expire over time (simple buff like Arcane Intellect) and those that are dependent of the environment around you like the area over effect (AoE) effect given by totems. When you are close to them you get thier buff and when you are far you don't. Some AoE buffs are given when you are in a deffined zones.
You can dismiss an active buff that expires over time by right-clicking on its icon. Most buffs do not stack with other similar buffs. One prominent exception is heal over time spells (HoT), heal over time spells from multiple characters and different heal over time spells from the same character (such as a druid's Regrowth and Rejuvenation) will stack with eachother.
The debuffs are the opposite of the buffs. A player or encounter can give you a debuff. It effect can be to slow you to stun(you lose control of your cahracter and can't move), to fear(the target of it flee and lose control of his character), to silence(you can move but can't cast any spells) and etc... The damage over time effects (DoT) are also considered as a debuffs.


2. Class Buffs.
Death knight:
- Abomination's Might - Increases your group's Attack power by 5,10% and own Strength by 1,2%.
- Horn of Winter - Increases your group's Strength and Agility for 2 minutes, 3 minutes with Glyph of Horn of Winter.
- Improved Icy Talons - Increases the melee and ranged attack speed of group by 10%, and your own attack speed by an additional 5%.
Druid:
- Mark of the Wild/Gift of the Wild - armor, all attributes, and resistances for target/target's party.
- Thorns - reflective damage for target.
- Innervate - massive short term mana regeneration for target.
Hunter:
- Aspect of the Pack - Increases group movement speed by 30%. If struck in combat, will stun you for 4 seconds.
- Aspect of the Wild - Increases Nature Resistance for the group.
- Trueshot Aura - Increases Attack Power for the group by 10%. Marksmanship Talent.
Hunter pet:
- Roar of Courage - Increases Strength and Agility of group members. Available to Cats and Spirit Beasts.
- Qiraji Fortitude - Increases group members' Stamina. Aura.
Mage:
- Arcane Intellect - Increases maximum mana and spell power.
- Focus Magic - Increases the target's chance to critically hit with spells by 3%. When the target critically hits your chance to critically hit with spells is increased by 3% for 10 sec. Cannot be cast on self.
Paladin:
- Auras - Auras affect the Paladin's party/raid.
- Devotion Aura - Increases armor.
- Retribution Aura - Reflects damage onto attackers.
- Concentration Aura - Lose 35% less casting or channeling time when damaged.
- Resistance Aura - Increased fire, frost, and shadow resistance.
- Crusader Aura - Increases Mounted speed by 20%. Does not stack with other speed increasing effects.
- Blessings - Blessings affect everyone in a paladin's party/raid. Only one blessing can be active on a party/raid per paladin at a time. Blessings can also be put on single targets only if the target is not in your party. All Blessings last 1 hour.
- Blessing of Might - Increases attack power by 10% and restores mana based on level.
- Blessing of Kings - Increases Strength, Agility, Stamina, and Intellect by 5% and increases magical resistances by level. Note: Kings is exactly the same buff as a Druid's Mark of the Wild.
- Hands - Hands are very short term buffs that affect only a single group member.
- Hand of Reckoning - A paladin's taunt. Usable against mobs to get them off others in the group.
- Hand of Protection - Target is protected from all physical attacks for 10 seconds, but during that time they cannot attack or use physical abilities.
- Divine Protection - Target takes 20% less damage for 10 seconds.
- Hand of Freedom - Target is granted immunity to movement impairing effects for 6 seconds.
- Hand of Salvation - Target has their total threat reduced by 2% every 1 sec. for 10 seconds.
- Hand of Sacrifice - Target transfers 30% damage taken to the Paladin. Lasts 12 sec or until the Paladin has transfered 100% of their maximum health.
- Beacon of Light - Direct heals from the casting Paladin also heal the Beacon if the target is within 60 yards. Not affected by Line of Sight.
- Seal - Seals grant bonuses to the Paladin and allow the use of Judgement.
- Seal of Righteousness - Grants each single-target melee attack additional Holy damage.
- Seal of Insight - Gives each single-target melee attack a chance to heal the Paladin and restore 4% of the paladin's base mana.
- Seal of Truth - Causes single-target attacks to Censure the target, which deals (additional Holy damage over 15 sec. Censure can stack up to 5 times. Once stacked to 5 times, each of the Paladin's attacks also deals 15% weapon damage as additional Holy damage.
- Seal of Justice - Causes each single-target melee attack to limit the target's maximum run speed for 5 sec and deal additional Holy damage.
Priest:
- Power Word: Fortitude - Increases Stamina for group. Lasts 1 hour.
- Power Word: Shield - Shields a target from some damage. Lasts 30 seconds.
- Power Infusion - Increases spell casting speed by 20% and reduces the mana cost of all spells by 20%. Lasts 15 seconds.
- Shadow Protection - Increases Shadow resistance for group. Lasts 1 hour.
- Fear Ward - Wards the friendly target against the next Fear attack. Lasts 3 minutes.
Rogue:
- Tricks of the Trade - Redirects all threat caused by the rogue's attacks to the targeted raid member for 5 seconds, and increases their damage by 15% during this time.
- Master Poisoner - Increase the critical hit chance of all attacks made against any target you have poisoned by 1,2,3%.
- Savage Combat - all physical damage caused to enemies you have poisoned is increased by 2,4% Shaman:
- Bloodlust/Heroism - Increases casting and attack speed by 30%.
- Elemental Oath - While Clearcasting is active, group members receive a 3,5% bonus to their critical strike chance. Elemental Talent.
- Unleashed Rage - Increases all group members attack power by 5,10%. Enhancement Talent.
- Ancestral Healing -Reduces physical damage taken by 5,10% for 15 sec after receiving a critical heal. Restoration Talent.
- Earth Shield - Shields the target, reducing casting or channeling time lost when damaged by 30% and causing attacks to heal the shielded target. Lasts 10 minutes. Restoration Ability.
Earth Totem:
- Strength of Earth Totem - Increases the Strength and Agility of the group.
- Fire Totem:
- Flametongue Totem - Increases Spell Power of the group by 6%.
Water Totem:
- Healing Stream Totem - Periodically heals group members.
- Mana Spring Totem - Periodically restores mana to group members.
- Elemental Resistance Totem - Increases Fire, Frost, and Nature resistance.
Air Totem:
- Windfury Totem - Increases melee haste of the group by 10%.
- Grounding Totem - Redirects one harmful spell from a group member to itself.
- Wrath of Air Totem - Increases spell haste of the group by 5%.
- Water Breathing - Target can breathe underwater. Lasts 10 minutes. Requires Shiny Fish Scales. Reagent removed with Glyph of Water Breathing.
- Water Walking - Target can walk on water. Lasts 10 minutes Requires Fish Oil. Reagent removed with Glyph of Water Walking.
Warlock:
- Unending Breath - Underwater breathing for target.
- Detect Invisibility - Increase detection of invisibility for target.
- Demonic Pact - Adds a percentage of the Warlock's spell power to all party or raid members on minion crit.
Imp:
- Blood Pact - Health for Warlock's party or raid.
Felhunter:
- Fel Intelligence - Increased Spirit and Intellect for Warlock's party or raid Warrior:
- Battle Shout - attack power.
- Commanding Shout - health.
- Stance - A warrior's stance affects which abilities they can use and also provides additional benefits for the warrior.
- Battle Stance - Increases damage done by 5% and decreases damage taken by 5%.
- Defensive Stance - Decreases damage taken by 10% and increases threat generation.
- Berserker Stance - Increases damage done by 10%.