To answer your last question, yes. And if you lowered the external pressure, like in my log cabin at 7,000 feet, then the boiling point would decrease. My water boils at a much lower temperature than yours, and it takes me forever to boil an egg since my boiling water is so cold.
So if you have some water, it will naturally have a (small) vapor pressure. If you add heat to the water, its vapor pressure will rise. This kinda makes sense because warmer water jiggles around more, so more molecules at the surface will jiggle off of the water and become vapor.
Once you add enough heat, the vapor pressure will equal the atmospheric pressure and the water will be boiling. If you added even more heat, could you make the water even hotter and raise the vapor pressure even more? No, because if you add more heat to the water, it will boil harder, and the boiling process is a cooling process (it convert thermal energy into breaking hydrogen bonds and flinging water molecules into the atmosphere, thereby lowering your thermal energy).
We all know that if you keep adding heat to the water, it will eventually boil away. How much heat does it take to convert all of your 100C water into 100C steam? That is the heat of vaporization. Obviously if you double the amount of water you double the amount of heat needed, so sometimes we use joules per unit mass, which is a constant and something you can look up in a book.
