NATO's full form is North Atlantic Treaty Organisation.
NATO is a military alliance that was formed in 1949 by 12 countries, including the US, Canada, the UK and France.
NATO alliance has a total of 30 member countries - 2 North American countries, 27 European countries and 1 Eurasian country.
An attack on one member state is considered as an attack on all
NATO's headquarters are located in located in Brussels, Belgium.
Russia wants NATO to bar Ukraine from joining NATO