How many countries are there in the world today?
There are 195 countries in the world today.
Unless you don't count Taiwan.
Taiwan is not considered an official country by many, which would bring the count down to 194 countries. Although Taiwan operates as an independent country, many countries (including the U.S.) do not officially recognize it as one. Because the People's Republic of China considers Taiwan a breakaway province of China, countries who wish to maintain diplomatic relations with China have had to sever their formal relations with Taiwan (more than 100 countries, however, have unofficial relations with Taiwan).
For more on this subject, see: How Many Countries Are There?