Communication skills are about saying the relevant stuff verbally and non-verbally, making friends by doing the 'give and take'. Communication skills are more than verbal and non-verbal communication. They are also about making a good impression, about having a presence and so on.
Here are some communication skills facts from the internet: 1. 95% of divorces are caused by a "lack of communication". 2. We listen at a rate of 125-250 words per minute, but think at 1,000-3,000 words per minute. The figures may not stand up to scrutiny but there is some truth in these facts.
Basically, we need good communication skills to succeed at job interviews, negotiations, presentations, public speaking, and to move ahead in our professional lives.