Students stand outside a building to find an Internet signal for their phones in Havana, Cuba, on April 1, 2014. (AP Photo/Ramon Espinosa, File)

According to official Cuban government statistics, some 23 percent of Cubans are on the Internet. But when the White House announced the President Obama's new approach to Cuba, it railed against that country's "Internet penetration of about five percent—one of the lowest rates in the world."

So what's with that considerable gap, which represents whether about 2 million Cubans do or don't go online?

It's a matter of definition. The Cuban Internet is different from the Internet that most of the rest of the world knows. And on the Cuban version of the Internet, there is no Twitter, no YouTube, few blogs or publications from the United States or elsewhere beyond the boundaries of that island nation. Instead, explains Internet researcher Sanja Kelly of the pro-democracy group Freedom House, that Cuba-wide web is limited to a national e-mail system, some government-approved Web sites, a Cuban encyclopedia, and little else.

Indeed, Cuba has its own Internet, thought the better term is probably Intranet, like you might have at work. Only an entire country is on it, and can't break past its borders.

Given the relative paucity of content on the Cuban Internet, explains Kelly, "most people just use it for e-mail."

Of course, there are other countries around the world that limit what their citizens can see online, including Russia and China. But Cuba, says Kelly, doesn't rely upon the same sort of technological filtering to restrict where online Cubans might go. Instead, she explains, the Cuban approach is uniquely far more binary. "The government prefers to limit access" -- to the full, global Internet, that is -- "through a total lack of connectivity and artificially high prices."

Who are the 5 percent of Cubans who can go where they'd like online? Doctors, government lawyers, party officials, and a handful of other "non-threatening" Cubans, reports Kelly. There are laws in place in Cuba that make it illegal for online service providers to allow access to the global Internet to those without a government-issued license.

Cuban officials have, in recent years, made public pronouncements about the need for Cuba to enter the digital age. Beginning in 2009, the Castro government began opening would become about a hundred Internet cafés around the country. But even there, subtle and not so subtle discouragements exist. Visiting international sites costs about seven times what it costs to get on the national Intranet, or about $4.50 an hour. Given that the average monthly salary in Cuba is about $20, those price differences can be an effective nudge towards sticking in the Cuban digital cul-de-sac.

And if that doesn't do it, explains Kelly, there are alerts that pop up telling users that their visits to non-Cuban Web sites are being monitored.

Some resourceful Cubans have found ways around the restrictions.

"A family member from abroad will bring a WiFi set-up and patch into someone else's 3G connection," explains Julia Sweig, director of Latin America studies at the Council on Foreign Relations. Younger Cubans in particular will hang around outside hotels -- where, inside, wealthy Cubans and foreigners can go online -- and hop on wireless connections using borrowed passwords. And, says Sweig, some Cubans have figured out how to have some benefits of the modern Internet though what some in the field call "sneakernets": they'll go online and download movies, music, and other materials and pass them around among friends and family on USB drives.

Will Obama's negotiations with the Cuban government, which includes the promised loosening of restrictions on the import and sale of laptops and other telecommunications equipment, actually make it easier for more Cubans to roam far more freely online? At least one high-profile critic of Obama's Cuba policy doubts it.

Sen. Marco Rubio (R-Fla.) slammed the Obama administration this week for failing to get any meaningful concessions that might bring more Cubans truly online.

“The president said that the people of Cuba do not have access to advanced, 21st century, modern technology for communications and telecommunications because of the U.S. embargo. That is false," Rubio said. "The reason why they don’t have access to telecommunications, like smartphones, like access to the Internet, is because it’s illegal in Cuba.”

"This notion that Cuba is going to allow the Cuban people access to any Web site they want," said Rubio, "is ridiculous."