I have installed slackware 14. It has an in-built support for TeX. The distributions provided are teTeX and eTeX. Does it make a difference if I install TeXLive 2013? Secondly, I am not able to compile the documents using XeLaTeX in slackware.I can compile only using PdfLaTeX and eTeX.What should I do?
The teTeX project has been dead since May 2006, when Thomas Esser announced he would not maintain it any more. See http://www.tug.org/tetex/ for information about this.
At the time, XeTeX was available only for Mac OS X; indeed it was added to TeX Live only in the 2007 release (see Section 9.1.4 of the TeX Live manual), so it's not surprising that what you get from Slackware doesn't have it.
In the last seven years, TeX distributions have grown and there are many packages that weren't available in 2006; many have been updated and also the binaries have been rebuilt and debugged several times.
So my advice is to install TeX Live 2013 from TUG
The distribution installs into its own tree, under
(where in your case
I usually advise to make a symbolic link