If a topic in a Wikipedia article is too complicated with jargons that are foreign to you, you can visit the simplified version of the article by replacing the “en” in front of the Wikipedia link with “simple”.
For example, the normal Wikipedia page for Stem Cells (http://en.wikipedia.org/wiki/Stem_cell) are full of scientific terms and is not an easy read for most people. Change the URL to “simple” (http://simple.wikipedia.org/wiki/Stem_cell) to get a “layman’s version” of the article.
Not all Wikipedia article have a simplified version. The “simple” version is not meant for any sort of in-depth research on the topic, but is useful to get a quick grasp of basic understanding on difficult topic.