What is the difference between BSD and GPL?

I know this is not about Rebol, but it would be nice if someone explain it :) Differences of BSD, GPL, LGPL? I'm not a lawyer, keep it simple :)

A google search of "gpl layman terms" found these: http://pthree.org/2007/08/08/bsd-license-explained-in-layman-terms/ http://www.cygwin.com/ml/cygwin/1997-09/msg00560.html

This is a quote from wikipidia ( http://en.wikipedia.org/wiki/Software_license ): An example of a copyleft Free Software license is the GNU General Public License (GPL). This license is aimed at giving the end-user significant permission, such as permission to redistribute, reverse engineer, or otherwise modify the software. These permissions are not entirely free of obligations for the end-user, however. The end-user must comply with certain terms if the end-user wishes to exercise these extra permissions granted by the GPL. For instance, any modifications made and redistributed by the end-user must include the source code for these, and the end-user is not allowed to re-assert the removed copyright restrictions back over their derivative work. Examples of permissive free software licenses are the BSD license and the MIT license, which essentially grant the end-user permission to do anything they wish with the source code in question, including the right to take the code and use it as part of closed-source software or software released under a proprietary software"license.

Thanks a lot. I've been always confused them, can I take part of a source code and use it in a closed source app. or my app. should be open source etc. kind of questions.