Everyone pulling the same way
When a fishing net is hauled in, a large group takes part and pulls in the same direction, and that makes the job easy.
Figure to be added
Because the force everyone applies acts in the same direction, the net comes in successfully. Here all the forces are applied collinearly, in one direction.
What does "collinear" mean here?
The rope hauling the net is one straight line. Everyone is holding that same rope, so every one of their forces has the same line of action. How long a line the people stand in makes no difference — what matters is not where they stand but the line they pull along.
Why pulling together matters
One person cannot haul the net, not because they have no force but because their force is not enough. When ten pull together those ten forces add and act as one.
Now let us look at how the resultant of two collinear forces acting in the same direction is found — with two balances instead of people.