The definitions seem kind of arbitrary, online friend seems to mean either:

1. friend who you primarily communicate online

2. friend where initial contact was made online

Option 1 seems odd, especially for friends who have moved. Are they reclassified as "online friend"? Option 2 represents only a single moment in time and seems to have little bearing on everything past that initial contact.

Also some people seem to classify "real friend" as "friend that I physically see on a regular basis".