OTF is a modern extended version of TTF, with more features. Downsides are it can be bigger in filesize and could even take longer to load. But that is not really relevant for modern computing and one should default to OTF, unless there is a good reason to use TTF variant (if both are available).
As far as I understand it, TTFs are more basic, while OTF can have more features and glyphs.
OTF is a modern extended version of TTF, with more features. Downsides are it can be bigger in filesize and could even take longer to load. But that is not really relevant for modern computing and one should default to OTF, unless there is a good reason to use TTF variant (if both are available).