What Is Monospace?
In a monospace font every character occupies the same horizontal width — an "i" takes as much space as an "m." This even spacing makes columns of text align perfectly, which is why monospace faces are standard for code editors, terminals, and tabular data.
Monospace type comes from the typewriter, where each key advanced the carriage by a fixed amount. Programmers adopted it because aligned characters make indentation, brackets, and columns easy to scan.
Proportional fonts (the opposite of monospace) vary each character's width for a more natural look, but they break the strict vertical alignment that code relies on.