CSV

A comma-separated values (CSV) file is used for the digital storage of data structured in a table of lists form, where values for a  particular record are stored on one line, each separated by a comma. Each line in the CSV file corresponds to a row in the table. Hence a newline character is used to indicate the end of a record. Within a line, values are separated by commas, each value belonging to one column.

History
This format has its origins in the early era of computing and is widely used  in cases where information has to be passed in between different  computer systems that differ in schema, processing speeds and formats.

Concepts
CSV is one specific implementation or variation of a delimited text file,  all of which use a certain specific character to separate the fields or  values of one record. One more specification of the CSV format, is that it uses a " (double inverted comma) around fields that contain reserved  words, instead of using a \ (backslash) or some other escape character.

Standards
No general standard specification for CSV exists. Variations between CSV implementations in different programs are quite common and can lead to  interoperation difficulties. For Internet communication of CSV files, an Informational IETF document  (RFC 4180 from October 2005)  describes the format for the "text/csv" MIME type registered with the  IANA. Another relevant specification is provided by Fielded Text which also covers the CSV format.