The ISI, JCR impact factor is considered as the best quantitative measure of the quality of a journal and its research papers. Every researcher tries his best to get his research paper published in an impact factor journal but researchers rarely know what is an impact factor? The impact factor is basically a standardized measure of the Institute of Scientific Information (ISI). It measures the way a journal receives citations to its articles over time. It is calculated in such a way that the number of current citations a journal receives to articles published in the two previous years are divided by the number of articles published in those same years. For example, the 2009 impact factor is the citations in 2009 to articles published in 2007 and 2008 divided by the number of articles published in 2007 and 2008. The resulted number is considered as the average number of citations the average article receives per year in the proceeding two years of the publication year.