The Population Reference Bureau addresses the topic of "How Many Countries Are in The World?" and kindly mentions yours truly as a source. While I count 195 countries in the world, the PRB post reports that on their World Population Data Sheet they compile data for 240 geopolitical entities. The number 240 includes 45 entities that are not independent but have some affiliation with an independent country.

Comments
That is an honor to be cited as a source, despite very minor difference, but clear differences in bases for counting the countries
I worked for Merck Pharmaceutical in a chemistry and micro lab,and met a microbiology lab tech who grew up in Tijuana. She was the only survivor of 9 girls who had ovarian cancer from one neighborhood. They had a dump in that neighborhood…contaminated. I don’t know the history of that dump, but I believe everyone needs to be responsible. Plastic takes, I believe, 50 something years to breakdown, and I like the way you explain the difference.
the number 240, it does not just include countries, but also some totally independent areas.
It’s very nice that so many countries are in the world. Many cities are there & also lack of people.