Just saw this article on CNN
about Japan having the most powerful passport, with the largest number of visa-free and visa-on-arrival access to 190 countries:
Henley Index: Japanese passport now world's most powerful Updated 9:34 AM ET, Tue October 9, 2018 (CNN) - There are few things more liberating than travel -- although some passports offer more freedom than others.
A new report published October 9, 2018, reveals just how many borders some travel documents can cross.
According to the Henley Passport Index, compiled by global citizenship and residence advisory firm Henley & PartnersCitizens, Japan now has the most powerful passport on the planet.
Having gained visa-free access to Myanmar earlier this month, Japanese citizens can now enjoy visa-free or visa-on-arrival access to a whopping 190 destinations around the world -- knocking Singapore, with 189 destinations, into second place.
Germany, which began 2018 in the top spot, is now in third place with 188 destinations, tied with France and South Korea.
Uzbekistan lifted visa requirements for French nationals on October 5, having already granted visa-free access to Japanese and Singaporean citizens in early February.
South Korea gained visa-free access to Myanmar on October 1, while Paraguay removed visa requirements for Singaporean passport holders in 2017.
The United States and the UK, both with visa-free or visa-on-arrival access to 186 destinations, are in fifth place. With neither having gained entry to any new jurisdictions this year, it seems unlikely that either will soon reclaim the No.1 spot they held in 2015.
The CIA's World Fact Book says there are 267 world entities.
So how do countries (entities?) work out who can travel where with just a passport? I've read some of the other links about entry not being allowed for having a record or for having been denied previously. I'm asking about what seems like a higher level thing.
Also I'm thinking tourist kind of access, not as a private business person.