What exactly is constipation?

It depends. Constipation is the inability to have a bowel movement. Some patients only have a bowel movement once every 3 days, but they are not constipated. However 95 percent of patient should have a bowel move within days. Patients who only go to the bathroom 2 times or less per week are constipated. If the is a new symptom, you should see a gastroenterologist.
Hard stools. Excessiveley hard stools or dessicated stools. Fecal material with less water content.

Related Questions

Can you please tell me what exactly is constipation, and what are ways to help it?

See below. Constipation occurs when you are not emptying your bowels well - often the stool is hard and dry. Try to eat at least 5 servings of veggies per day & 4 of fruit. Hydrate well. Avoid junk carbs & don't overdo the dairy. Stay physically active.