What does Candela mean?

Candela is the unit of luminous intensity at any point measured at a given angle of radiation. One Candela is equivalent to the luminous intensity of one candle at a distance of 1 meter. As the beam becomes more concentrated, the beam angle will become proportionally narrower. Since Candela is the luminous flux within a beam angle, the intensity ("the number of Candela") will be higher with a narrower beam.

So why is the amount of Candela not stated on all packaging? This is because a regular bulb radiates in all directions. Light units such as Candela are therefore only applicable to spotlights and reflector lamps.

The relationship between the above terms in one image: