Abscesses occur when an area of tissue becomes infected and the body's immune system tries to fight it. White blood cells move through the walls of the blood vessels into the area of the infection and collect within the damaged tissue. During this process, pus forms.
cognition cogÂ·niÂ·tion (kÅg-nÄ­sh'Én) n. The mental faculty of knowing, which includes perceiving, recognizing, conceiving, judging, reasoning, and imagining.
Knowledge is defined as what is learned, understood or aware of. 1  An example of knowledge is learning the alphabet. 2  An example of knowledge is having the ability to find a location. 3  An example of knowledge is remembering details about an event.