A scalar quantity is simply a magnitude or number measurement like length, area, etc.
A vector quantity is both a magnitude or number measurement AND direction like the velocity of a car would give both magnitude and direction the car is traveling.
The resultant force , which is a vector quantity is the result of a system of forces.
example: if two people were on opposite sides of a table pushing the table forward with equal forces in opposite directions the table would not move, resultant force would be zero. but if each has a different force, the table moves in the direction of the resultant force.
person A pushes east 50 Newtons
person B pushes west 30 Newtons
50 N east - 30 N west = 20 N east
Resultant force is the table moving 20 N east
since it's a vector quantity it has magnitude (scalar quantity) 20 N and direction east
