Whats the difference between encyclopedia and encyclopaedia?
Strictly the second one should be ‘encyclopædia’. Because æ and œ have never appeared on keyboards the printing convention is that, in British English, they should be printed as separate letters where they come from Greek or Latin words. The Americans have gone further and dropped the ‘a’ (or ‘o’) as well. British English prefers to keep the extra letters in order to retain the long “ee” sound, because with a single ‘e’, the surrounding consonants would indicate a short sound, as in “pedal”. Æ and œ are still printed that way if the words are from Old English; French; Danish; Icelandic or Norwegian.