Templar is a unique class that can deal weapon damage and use the powers of light and burning sun to damage enemies. They can also act as healers, with dedicated restoration spells. It is the “paladin” of Elder Scrolls Online.

Here is the first Veteran map that you come across

There are three lines of class skills that a Templar can master. You can chose a primary path for your character and spend skill points for this line only or you can distribute your skill points between several branches. This will allow you to create your own class. Don't forget that you can mix class skills with other abilities: weapon, armor, racial etc.

 
Templar is a very interesting class because of his ability to heal. With a uniqueness in the variety of healing abilities and auras. There is no other class in Elder Scrolls Online who can restore allies’ health as fast as a Templar does it. The Templars healing spells also allow players to create different builds, with elements of restoration magic. This gives players the option of creating a mix of a healer and damage dealer. You can also play as a true healer with light armour and focus on supporting your friends in battle.

All you need to play as a damage dealer is to place damaging spells on your hotbar and put on appropriate gear. So don't feel that it is simply a healer archetype as it also has great attacking spells. Nothing stops you from being a true DD, never using restoration magic.