Bacterial Clustered Regularly Inter Spaced Palindromic Repeats (CRISPR) Associated proteins in association with a short guide RNA discovered as a bacterial adaptive immunity in the 20th century nowadays became a breakthrough gene editing tool in the arena of biomedical science and bioengineering. Historically, it was first identified as how bacteria maintain its genome integrity through a targeted endonuclease of any exogenous invading genetic elements either from plasmid or viruses by storing a memory of the first infection, expression of spacers and interference. Recognizing how it works, humans nowadays, are able to reprogram it using computer databases and genetic engineering knowledge and tools to cut and edit the genome at a targeted site for cancer therapy, viral therapy, and gene disruption for bioengineering purposes. They were also able to deactivate its endonuclease properties and making it only bind to the target site and act as a reporting signal in cooperation with other chemicals to indicate the presence of the genome so that it is being used as a diagnostic procedure for several diseases. However, the role of the system in repairing the broken DNA is unexplained or null. So in this detailed review, the historical discoveries, the mechanisms, processes, challenges and future research focus of the CRISPR/CaS9 how the system will be harnessed and un erroneously repairs the introduced break are discussed.