5 Sites for Learning Online, Free of Charge

Khan Academy has been a presence in online education since 2008, and according to their own site has delivered well over 400 million lessons to people in subjects as varied as the human respiratory system, NASA aerodynamics and engineering, differential calculus and elementary biology.

The site was founded as an effort by Sal Khan to tutor his cousin, and over time ballooned into a monumental testament to the charitable nature of teaching and the willingness of people to learn. Funded by donations, Khan Academy has benefited in the past from a million dollar gift by Bill Gates to encourage additional expansion of content and creation of educational videos.

Not only are the tutorial videos comprehensive and digestible, many of them come with attached course structures, that allow you to study subjects with a group of like minded students and discuss the things that you are learning, helping each other work through practice problems.

This is a community where people with information and skills can congregate and collaborate to write and improve educational books for all kinds of subjects, at multiple difficulty and experience levels.

While still a work in progress, there are greater than 10,000 live books in distribution on the wikibooks site, and all of them are available for download, browsing, and editing if needed. Wikipedia has been a trusted brand for access to information for over a decade, and is currently sponsoring access to it's content for people living in economically disadvantaged countries to promote education, so this is a unique opportunity for people to collaborate and improve the access to education for everyone in the world.

Topics are as wide and varied as introductory reading for children to organic and inorganic chemistry at the college level, with all disciplines imaginable in between. Much of the content is actually generated by students for other students, and the community encourages quality work and attention to detail.

As a standalone learning method or an accompaniment to others, Wikibooks offer a chance to gain detailed understanding of concepts and concrete examples that help a dedicated student understand material.

Often when studying a new topic, it is necessary to memorize and test your memory of new concepts, terms, and objects. Occasionally it is helpful to associate words with images, and this was traditionally the role of flashcards as a study tool.

Whether you are trying to pin down the names of 30 temples in India or the identities of the naturally occurring amino acids, memorize the symbols of the natural elements in the periodic table, or get your vocabulary test scores to 100%, you can do all of that and more within the Quizlet site.

While a basic level of use will allow you to input lists and output flash cards that you can use to study online or with a mobile application, advanced use allows you to create learning tools and games to help you learn using your own note cards as well as other people's note sets, and create comprehension tests in a number of different formats including multiple choice, free answer, and true or false.

While this method is a bit labor intensive if you are creating your own tools, you also have the benefit of having a learning experience that is completely tailored to your needs and only includes the information you are interested in mastering.

If you are willing to use other people's content, you can access banks of questions, definitions, and concepts for almost any topic imaginable. Quizlet claims that more people study using its site than any other site in the world, and the simplicity and utility of their application is enough for that claim to be believable.

While the first four listed resources have content in almost every discipline at multiple levels of difficulty, the last focuses in on programming with the intention of taking a complete neophyte and turning them into professional grade programmers and web developers.

Codecademy is an independent site that offers tutoring in the skills and knowledge of writing and implementing programming solutions for use in almost any way imaginable.

Content includes multiple programming languages, levels of initial knowledge, and degrees of complexity to allow people to progress gradually and build on skills as they are acquired.

While not as prolific in scale as the other sites mentioned, codecademy is unique in that it teaches a uniquely marketable skill in an accessible way to anyone, for free.

Although these are the top five sites for free online education, there are countless others. If you have used or would like to discuss other sites for learning online, please comment below.