How and why does sage cleanse energy and remove spirits?

Name: Arjun. DOB: 19 August 1989. POB: Chandigarh, India. TOB: 4:10 PM.

People always say sage is powerful for cleansing energy, but I’ve never really understood how it works. What happens when sage is burned? Does it purify the air scientifically, or is it about spiritual vibrations? How exactly does it remove negative energy and even unwanted spirits? I want to understand how this works.