According to the text, "mark" is a countable noun and is frequently used in the UK to refer to points given for a correct answer. In addition to being a symbol for points, a mark can also refer to a point given for doing well in an exam or competition. It is important to note that "mark" is only singular and the plural form is "points." Additionally, the verb form of "mark" can refer to designating something, leaving a physical mark, or labeling with a price or quality. Finally, "marks" are awarded for individual assessments while grades are given for entire courses.