Grep is a control line utility and it was originally written for operating with the Unix operating system. The default actions of grep takes a regular turn of phrase on the command line, interpret standard key or a list of files, and outputs the lines which holds matches for the normal expression. The term grep can also mean to locate globally for lines matching the standard expression, and print them. There are many command line switches accessible when using grep that change the default behaviour. It is a built-in function, which offers both a customary expression or a general code block and a record. It then returns the elements of that list harmonized by the expression. The Microsoft Windows platform offer a utility called "findstr" which accurately explains much of the functionality of the word grep.