Earning a degree, taking a class, or studying for a credential online is nothing new. In fact, it's becoming de rigeur in the education world. Why? It's flexible, it's affordable, and has that anytime, anyplace quality that makes it appealing to anyone with internet access.

Here are four surprising facts that you may not know about online studies.

1. Most online undergrads study online close to home

Online education prides itself as being accessible to nearly everyone, nearly anywhere. While that's true, most online students study largely close to home.

Last February, the Learning House, in conjunction with Aslanian Market Research, released their Online Students Learning Report, which contained some arresting findings. 

The report claims that two-thirds of all online undergrads took online classes less than 50 miles from a campus where they enrolled and nearly half studied online within 25 miles of campus. Over three-quarters -- 78 percent -- of online students enrolled at a campus within 100 miles of home. 

A mere eight percent of all online undergrads in the US take courses over 250 miles from home. 

In an article in Forbes, Learning House CEO Todd Zipper said, "It’s an important point to understand. Many people may think of online programs as amorphous, everywhere things but they are actually closely connected to the schools and the campuses -- both in the minds of students and in reality."

2. Online students are already one-third of all undergraduate enrollments

Based on federal data from a year ago, about 6.4 million students are enrolled in at least one online course, representing about one-third of all enrollments.

The report, Grade Increase: Tracking Distance Education in the United States, from the Babson Survey Research Group, found community college students were more likely than undergrads at four-year schools to take at least one online course.

3. There's more than one format

Online learning is not one-size-fits-all. They can range anywhere from the electronic versions of the correspondence course to high-level, interactive courses that require human interface. 

Some are recorded lectures, others have online discussion boards, and still others require live-group chats and discussions.

Some move at a prescribed pace and others let you work at your own pace. 

Choose the format that suits your needs best. Prefer a hands-off approach? Go for it. Need something with lots of visuals? Find a program that offers that.

If you're one of those people who needs deadlines to function, a self-paced course probably isn't your best bet. 

Online education also has a variety of options when it comes to the kind of credit you earn. You can earn traditional course credits, experience credits, apply your MOOCs for credit, or create a more traditional degree program.

The beauty of online learning is that you have a lot of autonomy in selecting the type of online experience that set you up for your best work.

4. It's environmentally friendly

Online learning requires no paper and no travel. While the parts in computers and mobile devices are not necessarily eco-friendly, producing and offering online learning options uses comparably less energy than producing a face-to-face course in which students and teachers meet. 

There's no printer ink, no printer, no paper, and fewer natural resources than it takes to build and maintain a campus building -- but there's still a cost. You need a device. And you need internet. And you need to care for them responsibly.