Games : Do I need to buy the game client in addition to Warlords of Draenor Standard Edition purchase?

My question is that if I buy warlords of Draenor Standard Edition as mentioned here:

https://eu.battle.net/shop/en-us/product/world-of-warcraft-warlords-of-draenor

Does this pack include download of a WOD client? Or do I have to explicitly buy client?

Asking this question as I am new to WoW.