Firstly, there is not just 1 ITF – there are 3 organisations with the name ‘International Taekwon-Do Federation’. The main difference between the 3 ITFs and the WTF is that the 3 ITFs promote Changheon-yu Taekwondo and the WTF promotes Kukki-won Taekwondo.
The ITF (International Taekwon-Do Federation) was founded by Choi Hong-hi in 1966, and promotes his style of Taekwondo – known as Changheon-yu Taekwondo (or ITF Taekwondo). The ITF later split into 3 separate organisations after Choi’s death, after disagreement over who should succeed Choi as president of the organisation.
The WTF (World Taekwondo Federation) was founded in 1973 by those Taekwondo practitioners who had not joined Choi in the ITF. The WTF was later able to get its style of Taekwondo to be a medal sport in the 2000 Olympic Games.
The WTF has had its headquarters in Seoul, South Korea since it was founded, and has the support of the South Korean government. The headquarters’ of the 3 ITFs have mostly been based in other countries – initially Canada, but now in the United Kingdom, Austria, and Spain.