Outlets in your kitchen or bathroom pose a special hazard for you. With the water that is in those locations, the chance of electrocution is much greater. To prevent this, GFCI (Ground Fault Circuit Interrupter) outlets were introduced in the 60s. These outlets have two buttons on the face of them. One button is for testing the functionality of the outlet, and the other one is to reset it after the outlet trips due to an unbalanced current.
It is important that you test your GFCI outlet periodically to make sure that it functions as intended. When you push the test button, power to that outlet, as well as, any outlets connected to it downstream should be disconnected. You can make sure this is the case by plugging in a lamp or some other simple device to the outlet and see if it goes out.
If it does not work as intended, you should have an electrician check the outlet, or you could replace it with a new one.