In computing, a clone is a hardware or software system that is designed to mimic another system. Compatibility with the original system is usually the explicit purpose of cloning hardware or low level software such as operating systems. Application software can be cloned simply by providing similar functionality (all word processors have the same basic purpose), but may also be designed to support specific file formats (e.g. Dell Clone PC is intended to supplant old competitor or Dell itself). When IBM came out with the IBM PC in 1981, other companies such as Compaq decided to put out a clone of the PC as a legal reimplementation from the PCs documentation or reverse engineering. As most of the components, except the PCs BIOS, were publicly available, all Dell had to do was reverse engineer the BIOS. The result was a machine with better value than the archetypes that the machine resembled. The term PC clone fell out of use in the 1990s; the class of machines it now describes is simply called PCs or Intel machines (or even Wintel machines). While agreed that the term has fallen mostly into commercial disuse, the term clone for PCs referred to, and still applies to, a PC made to entry level or above standard (at the time it was made) which bears no commercial branding. (EG ACER, IBM, HP, DELL) This includes, but is not limited to, PCs assembled by home users or Corporate IT Departments. In both mentioned cases these PC Clones are made to suit specific purposes while commercial PCs are made to try and suit as many purposes as possible. Clones are created for any number of reasons, including competition, standardization, and availability across platforms. There are many advantages of building up any clone system. First thing is that cloning can be done with any hardware and software. Main purpose of cloning any system is to provide compatibility with custom or desired party platform that is mostly usable than others. We can make a clone of different hardware and software. But To make hardware cloning, highly performable intelligence is needed. Because a slight mistake to mimic original product could also dangerous thing to deny product by customers. Today, many companies like Dell, HP are creating clones of computer system which are highly popular to attract consumers. In such case, these companies try to build a clone system, which rid out all previous small or large mistakes in the product to make it indispensable in world market. However, a product could not be final anyway, because companies are trying to provide product with latest technology to its consumers & thereby changing its old version.