What occurs when Imperfect Information exists in a Labour Market?

-Perfect Information refers to Workers knowing Everything about Every Job and Employers knew Everything of every Potential Worker. This obviously is not the Real World so -Many Workers end in Jobs that are not the Best Fit for them, which may not be paid Enough for them. Or have no Job at all -Employers have Workers that are not as Productive as they could be, leading to a less Competitive Firm