Font size refers to the height of characters in a typeface, typically measured in points (pt). A point is a unit of measurement equal to 1/72 of an inch. Common font sizes range from 8 pt for small text to 12 pt for standard body text, while larger sizes like 18 pt or 24 pt are often used for headings or titles. Choosing the right font size is essential for readability and accessibility. Smaller sizes may be difficult to read, especially for individuals with visual impairments, while larger sizes can help emphasize important information. Proper font size contributes to effective communication in documents, websites, and other media.