Skills suggestion based on: your peers are proficient with this skill

Hi,

How does it work this suggestion in Skills Center? what does it mean exactly peers in this context?

Does "peers" in this context mean employees (only direct reports) under the same manager?

And what means proficient in that context? will this suggestion come only for the Skills with a proficiency level or also the Attained (but not rated) Skills are suggested?

Thanks

Regards

Francesco