The pitch A above middle C vibrates 440 times per second. That is very fast and it is somewhat difficult to see this process happen even if you can see down the singer throat. Since the invention of the strobescopy it has become easier to view the vocal cord resonation process. If the vocal cords begin to come apart, the tone becomes breathy and the muscles around the outside of the larynx begin to tense. This becomes what is called a constricted phonation and is quite harmful for the voice.
This is a very brief and condensed version of what happens when you sing, there is obviously a lot more going on. But, to give you an idea of what is correct, take these two ideas and while you are singing, monitor them. See if you can keep your larynx still and your cords together. You will probably find that there is a certain area of your voice that is easy for you to accomplish this, and certain points of your voice that are more difficult. These harder areas are called bridges, and to find out more about those continue browsing this site.