What it is
Making yourself understood, and understanding others: talking, listening, giving feedback, asking for help. It shows the other person you care enough to be clear.
How it shows up for me
I learned this one the hard way, in a relationship where communication broke down. After that, I promised myself I’d never let it slide again, and that I’d aim for nonviolent communication, not just more talking. At work it’s the same skill. Most problems I’ve seen in teams were communication problems wearing a different costume.