Revenue = all income combined (client fees + fixed other income + one-off income). What comes in before deducting costs.
Margin = revenue minus direct costs (client costs and variable costs per client). Expressed in % or euros.
Profit = revenue minus all costs (client costs + fixed costs + one-off costs + team member costs). What's left for you as the agency owner.
On the dashboard all three are shown side by side so you can see at a glance whether a dip in profit is caused by less revenue or by extra costs.