Confused about skills on a guide

[Mhatos 0]

Hey everyone! So, I'm kinda new to the game and this is my first season. I was going through the fresh 70 guide for demon hunters and I don't understand the active skills displayed on the guide. Some of them are on the same "row" (Rain of Vengeance and Strafe are on the 4 key). Can I use both of them? And if yes, how do I do it? 

[Bubble181 15]

There's an option in the Gameplay menu to activate "elective mode" or whatever they're calling it these days, which will allow any skill to be slotted to any skill bar location (except for the left mouse button, can't place passives there).