What does light, reduced-fat and low-calorie mean?

What the labels mean:

• FAT-FREE
• CALORIE-FREE
• % FAT-FREE
• CHOLESTEROL-FREE
• SATURATED FAT-FREE
• LOW-FAT
• LOW-CALORIE
• LOW-CHOLESTEROL
• LOW-SATURATED FAT

See also:
accessdata.fda.gov - General Provisions
accessdata.fda.gov - Nutrition labeling of food