A letter is a symbol written in a single line of text. There are many types of letters, including alphabetic, numeric, punctuation, mathematical, and others. Caratteri speciali

A font is a complete collection of letters, numbers, symbols, and other characters that make up a typeface. Typefaces can be monospaced or proportional, and can be serif or sans-serif.  A font file is a file containing a set of characters that can be used to display text on a computer screen. Font files are usually in the.ttf format.

The term "font" is often used interchangeably with "typeface," but it's important to note that there are some fonts that can only be displayed on a typewriter and cannot be displayed on a computer.