Simmering means that you are heating a liquid to a temperature that is close to a boil, but not hot enough to create bubbles. I simmer foods on a 3 or 4 temperature setting on an electric stove. You still need to stir occassionally when simmering as food may still stick to the bottom.
To saute is to cook in oil over heat. An example of sauteing would be to saute an onion in olive oil.
To marinate is to take food and soak it in a mixture of spices, oil, and possibly vinegar to make it more tender and flavorful. You can generally marinate food for a half hour to days depending on the dish.
You may hear the word mince a lot with garlic. Mincing is chopping something into very tiny pieces. Think onions on McDonals's hamburgers.
Julienne is such a fancy word for a simple cut. Julienne means to cut something into long strips. This can be done with many vegetables like carrots. Make it easy on yourself and buy a julienne peeler, a little gadget that makes perfect julienne strips.
This is a very basic cooking technique. To chop is to cut into small pieces. The pieces don't have to be uniform or exactly the same.
To dice is like to chop, but the pieces are smaller.
Slicing is when you cut completely through an object. Think of slicing cheese, or bread. Same principle goes for veggies, meat and fruit.
To brown a meat means to cook until brown. You may brown the sides of a roast on the stovetop before cooking in a crockpot or oven.
So, you have learned how to boil water and make rice...:
These very basic cooking terms will take you to the next level of cooking. Knowing the basics can really make a difference in your kitchen creations.