Verbal communication involves speaking using words or noises, while non-verbal communication uses sign language, gestures, facial expressions, and eye contact. Good communication skills include making eye contact, not swearing or shouting, not chewing gum or texting during conversations, speaking clearly, listening actively, and having a relaxed body language. Bad communication skills can negatively impact job interviews and presentations by causing boredom or intimidation. Egan's Soler theory proposes micro skills like facing squarely, keeping an open posture, leaning in, maintaining eye contact, and relaxing to engage the listener and make them feel comfortable.