If the subject is underexposed due to the deficit of sunlight and other lights, fill flash is supplemented to correctly expose the subject. Fill flash can produce a stellar outcome if leveraged deftly and accurately. Output of your shot will not pan out unless you balance your flash with the existing natural light. If you want a really good shot go for 30% flash and 70% natural light. Most pictures with flashed are used only indoors but fill flash can definitely spice up a photo outdoor.
