Search engines like Google find Web sites of all levels of quality. And anyone can write anything they want in Wikipedia.
These Web sites were chosen by a librarian based on certain criteria. Keep these things in mind when deciding if a Web page is reliable.
Always check with your instructor to find out if you can use free (non-Library) Web sites for your assignments. And if looking for journal articles, databases are the most efficient tool for searching. See the Articles tab.
For specific tips on recognizing reputable science articles, check out
Local, state, federal, and international governments and non-governmental organizations are excellent resources for health and wellness statistics.