International Baccalaureate (IB) is an alternative - or an opportunity - for you who want to do your upper secondary level (=high school) education in English. The IB Diploma program consists of two parts:
1) one pre-DP year that corresponds to the first high school year
2) a 2-year university qualifying high school program that opens doors in more than 130 countries.
The IB Diploma corresponds to the national matriculation exam (=ylioppilastutkinto). It is recognized by the Finnish law (Lukiolaki) and Finnish education system including all the universities and colleges. On May 1st, you cannot really tell who has done the national matriculation and who has done IB because everyone is wearing the same white cap. However, the lyre is different, and after the IB studies, you are different.
The International Baccalaureate Organization (a.k.a IBO) provides a lot of information about the IB Programme: for instance about the structure of the programme and the six subjects to study. Since this is an international programme, the requirements are the same everywhere.