What does the term 'kerning' refer to in typography?

The term 'kerning' specifically refers to the adjustment of space between individual characters in a word. This manipulation helps enhance the visual appearance of text by ensuring that the spacing looks even and harmonious, improving readability. The goal of kerning is to achieve a visually pleasing composition of letters, taking into account how they interact with one another based on their shapes.

In contrast, the other options focus on different aspects of typography. Adjusting brightness is related to the overall visibility of the text but does not pertain to the spacing between letters. The style of a font refers to its design characteristics, such as being serif or sans-serif, rather than the spacing adjustments. Lastly, the color used in text deals with the appearance of the text itself but does not involve spatial relations between characters. Thus, understanding kerning is essential for creating visually appealing and professional typography.