Can someone explain to me what copd is? it's chronic obstructive pulmonary disease but what is that exactly please?

COPD: COPD is an umbrella diagnosis and under that umbrella is emphysema, chronic obstructive bronchitis, and some will have an asthmatic component. Associated with cigarette smoke (including second hand), certain occupational exposures, and certain genetic abnormalities. It is chronic and progressive. Significant cause of hospital admissions/ md visits/ death!

Chronic Lung Disease: COPD is a disease of inflammation and/or destruction of the lung. Most often, it is from smoking cigarettes, but not always. There are two main components: chronic bronchitis, which is coughing up mucus every day; and emphysema, which is destruction of the lung tissue. Both conditions block air from completely exiting the lung causing symptoms. That said, it can be treated effectively and be well.