Chardonnay is one of the most widely grown and vinified wines in the world. This is because you can grow it in almost any climate where grapes can be grown. It's named after a town in the Mâconnais in France. Chardonnay is a very neutral grape to begin with, it doesn't have a lot of aroma, so the winemaker often uses a lot of techniques to affect the flavor and aroma of the wine. These include Malolactic Fermentation, Lees Stirring, and aging in oak barrels. Don't worry, I'll explain what those are later. Chardonnay is also one of the key grapes used to make Champagne.
In colder climates, Chardonnay will usually have lighter or medium body, flavors of green fruits, like green apple, and lots of acidity. In warmer climates, Chardonnay can take on more exotic notes, such as tropical fruit flavors like pineapple. In those areas, the wine will often be lower in acidity, contain higher levels of alcohol and be much fuller in body.
In the United States, the Chardonnay grape is what most people think of when they think of white wine. There have been times when Malolactic Fermentation and techniques like oak chipping were taken quite far, so that it tasted like a stick of butter or a piece of wood. Currently however, these techniques are used more sparingly.
Chardonnay from most parts of the world is a wine to be drank young. In the Burgundy region of France, however, Chardonnay can age phenomenally in the bottle, developing very complex nutty characteristics. Why does this only happen in France? No one really seems to know. None of those wines will come cheap, in case you were wondering.