Courier is a monospaced slab serif typeface made to look like the product of a typewriter. It was designed by Howard Kettler in 1955 and later redrawn by Adrian Frutiger for a series of electric typewriters.
Being a monospace typeface, each character occupies the same amount of horizontal space. Monospace style fonts were used often in early computers. Additionally, monospaced fonts are often used in making ASCII art (images created using fonts) due to their ability to maintain character alignment within different lines.
I find this font interesting mostly due to the fact that it’s a throwback to older type based technologies. The fact that the style of this “outdated” typeface is still relevant in certain circumstances to this day is particularly interesting to me.