Unit Frames for Healers

• As a healer, you constantly have to remove status effects from other players in your group. Unit frames make it easier to do this by alerting you when a player has received a status effect and color-coding the debuffs under the portraits of your group members. To make healing easier, you can also set your unit frames to alert you and change the color of health bars once they go below a certain point. To make sure you are always within healing range of your group, you can set the unit frames to turn your group members' portraits transparent upon stepping too far away from you.
  
  

Unit Frames for Tanks

• As a tank, your job is to protect your group and keep the monster your group is fighting from attacking anyone else. With unit frames, you can see an aggro meter, which shows you who has the most aggro or who the monster is likely to attack. This lets you know when you need to work harder to get aggro back.
  
  

Unit Frames for Damage Dealers

• Knowing when your cool-downs are available and when your offensive status effects wear off is one of the key jobs of damage dealers. Unit frames provide on-screen alerts letting you know when your abilities are ready to be used again. You can also use the aggro meter function of unit frames to keep yourself from getting too much aggro. This would cause the monster to attack you instead of the tank and force the healer to waste mana.
  
  

The Best Unit Frames

• The most popular unit frames are X-Perl and Shadowed. X-Perl contains casting monitors, which display bars on your interface while casting a spell. Shadowed has more options for customizing the way the floating windows look on-screen. They are both constantly updated and have development teams. Add-ons usually break after each patch, but updates are quickly made available for X-Perl and Shadowed unit frames.