The difference between Helvetica and Arial
Many people feel deeply about the use of Helvetica and Arial. The prevailing opinion is that Helvetica is a thing of beauty while Arial is an affront to the eye. The use of Arial in place of Helvetica tends to wind a lot of panties into a bunch.
These opinions may be rooted more in the history of these two fonts than in their design. The scorn may be more toward Microsoft than toward the angled terminals. Personally, I’ve got no opinion. Objectively, the differences are slim.
To make these differences clear, I’ve overlaid Helvetica in magenta with Arial in cyan, and shown their intersection in black. Here is a 75K PNG. If you want to look closely, here is a 152K PDF.