We frequently get asked about "outlets with buttons". The fancy name for those outlets is Ground Fault Interuppter (or GFI for short). But why do those outlets have buttons? Why do you need them?
GFI outlets are designed to cut off power before a dangerous electrical shock and/or electrical fire can occur. They are now the required outlet, according to national electric code, to be installed anywhere that is near water. Some examples would be bathrooms, kitchens, laundry rooms, and outdoors.
The GFI outlet monitors the electric current going out from it to whatever is plugged into it such as your hairdryer, coffee maker, washing machine, or iron. If the outlet senses the current has changed or is broken (so the current is going where it shouldn't), the outlet shuts itself off often as quickly as within 1/30 of a second so that no person is harmed and electrical sparking and/or fire doesn't occur.
GFI outlets should be tested monthly. To do this, plug a light into the outlet and turn it on. (Night-lights are great for this.) Hit the Test button. The reset button should "pop" out and the light will go off. Now press the Reset button in and the light should come back on. If the light does not turn off when you press the test button or if you cannot get the outlet to reset, then the outlet needs to be inspected by a licensed electrician to determine why it is not working correctly and ensure there is no underlying electrical issue.