Wikipedia is a "wiki" encyclopedia. A "wiki" is a software program that allows multiple people to collaborate by posting information and changing each other's postings.
The great thing about Wikipedia is that anyone can post to it. The bad thing about Wikipedia is that anyone can post to it. This is good because writers can share collective knowledge, correct errors, and improve the knowledge on the pages. This is bad because writers can share biased opinions and introduce errors, accidentally or spitefully.
In addition, content in Wikipedia can be changed at any time. This makes it unreliable as a reference source because others cannot reliably check on what YOU read in Wikipedia because it may have changed by the time they get there to read the entry.
Wikipedia is a decent start to your academic research and can give you good background information. But verify the information with other sources. Wikipedia does ask authors to post references at the end of articles so use those to find the original source. (But make sure that source is the original source and not just another secondary source.)
And unless your professor allows it, do not cite Wikipedia in your college assignments. Its changeable nature makes it an unreliable source.
Examples of errors and issues that have occurred with Wikipedia.
What do you think about Stephen Colbert's comment on reality? Does Mr. Colbert have a bias or political view? Does that affect the ideas he presents? How can you verify what is true? If you don't know, talk to a librarian!