Differences between .ttf and .otf

[Brad]

Since I'm a newbie in typography, I'm looking for a source (preferably a video) to understand the differences between .ttf and .otf files. I always thought OpenType features could only be implemented in .otf files (maybe due to the extension name), but I just realized in a .ttf file we could have contextual alternates and modified kernings.

[Ralf Herrmann]

 

[Ralf Herrmann]

Long story short: the suffix doesn’t say much.

• ttf is a font with TrueType outlines. It may or may not contain OpenType features.
• otf is usually a font with PostScript outlines. It may or may not contain OpenType features.