Food was not kept cold enough, hot enough, cooled fast enough, or cooked or reheated to the right temperature. Bacteria grow quickly in the "danger zone" between 41°F and 135°F, which makes this one of the most important food-safety checks.
Warewashing facilities properly installed, maintained, used; sanitizer concentration; test strips available and used
In plain English
Dishes, equipment, or surfaces that touch food were not properly washed, rinsed, and sanitized, or sanitizer was not at the right strength. Clean surfaces help stop germs from spreading to food.