Kerning is the small adjustment of space between individual pairs of letters so that text reads evenly. Some letter combinations leave awkward gaps or crowd together, and kerning nudges them until the spacing feels balanced to the eye.
Think of a row of books on a shelf. A thin paperback next to a fat hardcover leaves an uneven gap, so you slide them around until the spacing looks consistent. Kerning does the same for letters. A capital T next to a lowercase o, for example, leaves a visible hole unless you tuck the o slightly under the T’s crossbar. This is different from letter spacing, which spreads every character apart by the same amount rather than fixing specific pairs.
The pairs that cause the most trouble are usually the ones with angled or open shapes: an uppercase A beside a V, a W beside an A, or a capital followed by a comma or period. Designers learn to spot these on sight, because the gap reads as a small stumble even to people who could never name what is wrong.
Most of the time you never touch it, because quality fonts ship with kerning tables that handle thousands of pairs automatically. It becomes hands-on work for logos, large headlines and wordmarks, where one badly spaced pair stands out immediately. It pairs with broader whitespace choices, since the rhythm of a layout depends on both the gaps inside words and the space around them.
At TopDevs we let the font do the kerning in body copy and only fine-tune it by hand for client logos and big display headings, where the spacing is most visible.
