A clone is a genetically identical copy of a gene or of an organism. Gene cloning involves four steps: isolation, ligation, transformation, and selection. You can watch an interactive on gene cloning with this link: http://www.pbslearningmedia.org/asset/biot09_int_geneclone/
Cloning does have potential benefits such as organs for transplants or saving endangered species. It also raises concerns because it has a low success rate, clones are usually less healthy than the original animal, and cloning decreases biodiversity.
Watch the Cloning 101 video. video.