Entering a number into 'Min Salary' will exclude anybody with a minimum salary lower than this value e.g., if you enter £20,000, it will display results with anybody with a minimum salary of >£20,000.
Entering a number into 'Max Salary' will exclude anybody with a maximum salary set higher than this value e.g., if you enter £50,000, it will display results with anybody with a maximum salary of <£50,000.
Using minimum and maximum salary fields together will create a range e.g., if you put £20,000 in minimum and £50,000 in maximum, it will display results with anybody that fits the criteria of both a minimum salary of >£20,000 and a maximum salary of <£50,000.