Passports are far more than just simple travel documents that verify a holder's personal information.

In fact, the thin, palm-sized booklets also function as the barometers for a nation's status on the international stage -- in that some passports have the power to allow its holder to gain access to international destinations without extra entry requirements, such as visas, while some passports don't.

In this regard, a recent report showed that South Korean passports are one of the most "powerful" passports in the world.

According to Wednesday’s report released by English citizenship investment advisory firm Henley & Partners, as of the third quarter of 2023, South Korea has been ranked as the country with the third-highest passport index in the world together with Austria, Finland, France, Luxembourg and Sweden.

Passport indexes, based on the data from International Air Transport Association, are measured based on the number of countries the wielders of South Korean passports can travel to without a prior visa. As of July, South Korean citizens now have visa-free access to 189 destinations out of 227 around the world.

According to the firm's past reports, this is not the first time South Korea has ranked high on the list, in terms of its passport strength.

Since 2018, including the first half of 2023, Korea has been ranked as the country with the second most powerful passport in the world -- except for 2020, when the country ranked third on the list.

Having a "strong" passport connotes a slew of factors, according to Korea’s Ministry of Foreign Affairs.

The ministry said the concept of passport power indicates that the global society considers South Koreans' visits as having little chance of politically and diplomatically hurting the destination's reputation.

"Visa waiver agreements between two countries are mostly reciprocally contracted," a ministry official told The Korea Herald.

"If South Korea allows visa-free entry to a foreign country, that country typically bears the responsibility to permit visa-free entry to South Korean travelers. The fact that South Korea has one of the highest numbers of visa waiver agreements contracted in the world connotes that South Korea is received as a highly developed country worth allowing (inbound) visa-free travel to.”

He also said he understands the nation's high passport index as an additional possible indicator that South Koreans are internationally perceived as having little chance of overstaying their visa when traveling, and that countries view South Koreans' visits as helpful to their tourism industries.

According to Statista, a German platform specializing in gathering market and consumer data, South Korea ranked sixth in terms of countries with the highest outbound tourism expenditure worldwide in 2021. According to the platform, South Koreans spend some $16.7 billion annually while traveling.

South Korea's high openness to foreigners, in terms of many nations it permits travelers to cross its borders visa-free, might be another reason why the country has such a high passport strength, according to the Henley report.

The report said that although the connection between having a strong passport power and having open-door visa policies was not straight forward, it was noteworthy that South Korea -- which has the second-most smallest difference between its number of inbound and outbound visa-free entries -- has consistently retained high spots in the passport index ranking list in the last decade, while the passport powers of the United States and Canada -- which have large differences in numbers regarding inbound and outbound visa-free entries -- have dropped down the passport power list.

According to the report, holders of the US passport can travel 184 out of 227 countries visa-free, while the country itself only allows 44 other nationalities to pass through its borders without a visa.

However, experts added that there are limitations to viewing passport power as the absolute gauge meter for a nation's power, as there could be various reasons why a country prevents visa-free entry into a country.

"Visa grants are tightly related to geopolitical issues," said Lee Na-ra, an immigration lawyer at Hanjoong law firm.

"For example, the US forbids visa-free entry to anyone who has been to Iran even once. Chinese citizens have difficulty entering US soil as well. Diverse factors involving geopolitical reasons play into allowing or forbidding visa-free entry to a certain country, and, it may be that passport power does not wholly reflect a nation's power," she said.