Hii!
Non verbal communication means communicating without the use of language or speech. It is communication through body language and signs such as eye contact, facial expressions, distance between 2 individuals, posture and gesture.
The advantages include, easy to present and sometimes understand too, complementary to a verbal speech, help illiterate people, help people with hearing impairment, reduce time waste etc.,
You can elaborate on these points.
Hope this helps.
Good luck!