Just had a colonoscopy. the report said they found some aphthous ulcers in my bowel. what are they?

Ulcers in bowel: The ulcers associated with ulcerative colitis are located in the colon, whereas ulcers in crohn's disease may be found anywhere in the gut from the mouth (aphthous ulcers) to the anus. Ulcerative colitis ulcers are typically shallow and more numerous, while crohn's disease ulcers are usually deeper and with more distinct borders.