People who have gluten intolerance have intestinal systems that produce such a strong reaction to ingesting gluten that they cannot have any gluten at all.
When these individuals ingest gluten, their systems produce antibodies to the gluten. They may have all or some of the same symptoms and complications as individuals with Celiac disease.
In fact, Celiac disease is considered the most severe form of gluten intolerance. But there is a difference between someone with Celiac disease and someone who is just gluten intolerant. The difference is that the individual who is just gluten intolerant may not have any physical damage to their small intestines or the villi in their small intestines.