Humor a newbie. I'm extremely biased on this matter, so I'm taking extra effort to be somewhat objective.
All licenses have conditions and restrictions on use.
The GPL is no exception. However, since the GPL would require any software making normal system kernel calls to also be licensed under the GPL, Linus Torvalds included an exception. The BSD license has few restrictions. Basically the only conditions are that the copyright notice and warranty disclaimer follow the software. Both FreeBSD and the Linux distributions use a variety of licenses.