Proportional font means that each letter takes up a different amount of space depending on its shape. Imagine if you had a big letter M and a small letter i. The M would take up more space because it is bigger, and the i would take up less space because it is smaller. Proportional fonts also have different amounts of space between each letter depending on how wide the letter is. This helps make the text easier to read because it looks more like handwriting or natural writing, and makes it easier to fit more words on a page. So, some letters take up more space and some take up less, and there is space between the letters so they all fit together nicely.