Definition
A fine spacing adjustment that smooths out the awkward gap that appears when two letters of different shapes sit side by side. Every letter has its own bumps and dips, so the distance between certain letter pairs is tightened or loosened to make text look even at a glance.
Why do gaps seem to open up between letters on their own?
When you type on a computer, it places each letter in an invisible rectangular box and lines the boxes up side by side. If the boxes touch with no gaps, you would expect the spacing to look the same everywhere. But it doesn't, because every letter has a different shape.
Take a capital 'A' next to a 'V'. Big empty spaces open up at the top and bottom. Both letters slant, so even though their boxes touch, the eye sees a wide gap. Combinations like 'To' and 'Wa' do the same thing.
Sliding the two letters inward so they almost overlap, to fix this visual balance, is called kerning. It is the magic of filling the shape-based gap in a specific letter pair, so the letters flow together as smoothly as one word.
How is tracking different from kerning?
When people hear 'adjusting letter spacing,' many think first of the 'tracking' setting in word processors. But tracking and kerning work differently and have different goals.
Tracking widens or narrows the distance between every letter in the text by the same amount. It is like shouting to a line of people, 'Everyone, take one step back.'
Kerning, on the other hand, picks out only the space between two specific letters that look too far apart. It is like fixing only the seat next to a tall person or someone carrying bags. Kerning matters most in logos and big headlines, where the letters are large and gaps stand out.
To be a little more precise
To be a little more precise, modern digital fonts store kerning information for thousands of letter combinations in advance as numbers. When a type designer makes a font, they build in a table of rules, such as 'when V comes after A, tighten the space by this many font units,' inside the font file.
When software reads this table and adjusts the spacing automatically, it is called font-built-in metrics kerning. The clean, tidy text you read on websites and apps is thanks to the font maker's careful kerning work.
For print posters or brand logos, designers often don't leave it to the software's automatic calculation alone. They fine-tune the kerning by hand, in tiny steps. The visual weight the human eye perceives takes a subtlety beyond simple geometric math.
Common misconceptions
Kerning is just another word for the tracking setting in word processors, which tightens all the letter spacing at once.
Tracking adjusts the spacing between all letters in one go, but kerning is a technique that tightens or loosens only the spacing between specific awkward letter pairs, like 'A' and 'V.'
Where you meet it
When you write a lowercase 'o' after a capital 'T,' the 'o' is pulled slightly in under the T's crossbar, into the empty space.
When making large titles for movie posters or brand logos, designers adjust the spacing in tiny amounts so the letters don't look uneven.
In one sentence
Kerning finely adjusts the spacing of specific letter pairs to reduce the awkward gaps caused by letter shapes, so text reads naturally and evenly.