Helvetica or Arial?

Why are these two typeface are so similar? How do you tell them apart? What are the exact differences between these two fonts? The image overlays Arial and Helvetica on top of each other to help bring some of the subtle differences to light.

Helvetica

Designed in 1957 by Max Miedinger, Helvetica’s design is based on that of Akzidenz Grotesk (1896), and classified as a Grotesque or Transitional san serif face. Originally it was called Neue Haas Grotesque; in 1960 it was revised and renamed Helvetica (Latin for Switzerland “Swiss”).

Arial

Designed in 1982 by Robin Nicholas and Patricia Saunders for Monotype (not Microsoft), it’s classified as Neo Grotesque, was originally called Sonoran San Serif, and was designed for IBM’s bitmap font laser printers. It was first supplied with Windows 3.1 (1992) and was one of the core fonts in all subsequent versions of Windows until Vista, when to all intents and purposes, it was replaced with Calibri.

I Love Typography