What does "leading" refer to in typography?

Leading refers to the vertical space between lines of text in typography. This term originates from the days of metal type, where strips of lead were used to create space between lines, allowing for better readability and a visually pleasing layout. Proper leading can significantly affect the overall appearance of a block of text and its legibility. If the leading is too tight, text can become cramped and hard to read; if it is too loose, the text might appear disconnected or disjointed.

In contrast, decorative elements of a font refer to the visual style and flair of the characters themselves, rather than their spacing. The size of the font describes the height of the characters but does not address their line spacing. Alignment pertains to how the text is positioned on the page and is unrelated to the spacing between lines. Hence, leading plays a crucial role in how comfortably and effectively readers engage with text, making it an important consideration in typography.