Pay floor is the minimum pay or wages beyond which payment for work should not fall.
In other words it is the lower limit of pay or salary which should be given to an employee or a worker.
Sometimes separate industries have separate pay floors by having multi employer bargaining. These pay floors which are separately fixed industry wise may be changed by individual companies for themselves by negotiations.
The advantages of having a pay floor are many. They give protection to the least skilled employees by guaranteeing them some minimum wages. Also having a pay floor will push companies to increase their profits and productivity by making better use of their labor cost rather than by cutting labor cost by reducing the wage