Today there are 197 countries in the world:
193 UN members +2 UN observers + Taiwan+ Kosovo
The United Nations, as the most influential international organization, is often considered the start point for the correct counting the total number. All the 193 UN members are independent countries recognized worldwide.
Become a part of the United Nations is not so easy. First of all, the Security Council is voting and the consent of all 5 permanent members of the Council (the United States, the United Kingdom, France, Russia and China) is needed for the adoption of the new candidate. After that, the UN General Assembly approves this decision by no less than the two-thirds of the votes. Such a complicated procedure ensures that all the accepted UN members have been recognized by the vast majority of other states and have established diplomatic relations with them.
Two UN observers, Holy See (Vatican) and Palestine, are both countries, because the UN observer status confirms the certain degree of their international recognition. The Holy See maintains bilateral relations with the majority of the world through its 180 diplomatic missions in independent states and international organizations. Palestine nowadays is recognized by 137 countries.
All other self-proclaimed entities are considered as “partially recognized countries”. Some of them either do not control their own territory, like the Western Sahara, or are recognized only by 1-5 UN members and by partially recognized subjects like themselves. For example, the independence of the Northern Cyprus is confirmed only by Turkey; the Republic of Abkhazia has obtained acceptance of 4 members of the UN; the Nagorno-Karabakh Republic statehood is accepted only by three partially recognized states. The list may go on, but there are two exceptions:
Taiwan is recognized by 22 countries (21 UN members and one UN observer). This self-governed territory with a population more than 23 million people has all signs of statehood and plays the significant role in the region as one of the high developed economies in Asia Pacific. It participates in the World Trade Organization (WTO) and the Asia-Pacific Economic Cooperation (APEC). Taiwan has its diplomatic missions (official and unofficial) in more than 100 states and maintains the unofficial bilateral relations with the United States, Canada, UK, European Union, Germany, France, Russia, India, Australia, Japan, Indonesia, Philippines, Brazil, Argentina, Mexico, Turkey, Saudi Arabia, South Africa, Nigeria and others.
Kosovo is officially recognized by 111 UN states and by Taiwan. It also has obtained the membership of the World Bank, the International Monetary Fund (IMF), the European Bank for Reconstruction and Development (EBRD).
Such wide recognition of these two entities could be a basis to include Taiwan and Kosovo in the list of independent states. At the same time, China claims that Taiwan is a part of its internal territory, and Serbia does the same by insisting that Kosovo is its autonomous province.
Nowadays there is no consensus on the issue of the total quantity of countries, because still there is no universally agreed definition of “country” and there is no one single competent international body, which could correctly answer the question, “How many are there in the world?”.
All of the above is our own answer, which is based on the real practice of official and unofficial international relations existing today in the world.