By default the computer will assume that it's shooting an 18% grey card and expose the picture accordingly. There are a basically two knobs you can tune, to change this behavior.

One, you can decide what parts of the pictures are used in this calculation and how they are weighted. These are your spot, matrix, and middle measurement modes.

Two, you can use a creative program, e.g., night photography. That will treat bright highlights differently, AFAIK.

However, the world isn't really an 18% grey card and how you expose the picture depends on your creative intent. The most obvious examples are high-key and low-key photos. In fact, photographers often use 18% grey cards to determine the light conditions and then lock the exposure and white balance down and shoot manual. This way, they have a precise reading and no surprises. I only do that when I do portrait photography because skin tones and therefore white balance are crucial. In most other cases, I look at the histogram to see if the exposure is correct and use auto white balance.

You can always adjust white balance when you shoot RAW in post processing. However, you cannot fix the exposure if you're missing the data. That's why I use manual.