The CSV file extension stands for “Comma Separated Values.” It is a type of plain text files. There is only one difference between CSV and files called TXT or text files: the text in CSV is organized and the data is kept properly separated by commas. Another factor that differentiates CSV from text files is that each set of records is on a single line. Many times you will find a character that indicates the end of a record. This is in addition to the normal end-of-line character within a text file which is invisible. Since CSV files are better organized in terms of values, they are quite convenient for data manipulation in PHP, mySQL, and Excel. Therefore, it is better to use CSV when data input and output is required in tabular format. It can also be used as a common format between various applications.

The KML file extension stores geographic modeling information in XML format. This information includes lines, polygons, points, and images and is used to identify and label overlapping textures and locations. They are also used to create various camera angles and add HTML content. These KML extension files were originally used by Keyhole mapping software created by Keyhole Incorporated. This company was taken over by Google in 2004. As a result of this acquisition, KML files are now used by Google Earth and similar terrestrial navigation applications. Google Earth delivers a three-dimensional digital model of the Earth over the Internet using EarthStream technology.

The difference between the two types is that CSV files are similar to text files in that the text is more organized, whereas KML is used to store geographic modeling information.