W3Schools has focus on simplicity, practicing easy and straight-forward learning. It uses simple code explanations, and illustrates how to use it. The tutorials start from basic level, and move all the way up to complete professional references.
W3Schools was originally created in 1998, by Refsnes Data, a Norwegian software development and consulting company. The site derives its name from the World Wide Web (W3), but is not affiliated with the W3C.