CSV is an acronym that stands for Comma Separated Values. These types of files can also be read by Excel and most text based editor programs. It is a format where data is delimited by commas - and therefore sometimes also called a comma delimited file.
Documents that are CSV formatted look like the following:
155.550,Frankie Fire Dispatch,CH-1,FM
154.295,Frankie Fire Tactical,CH-2,FM
154.280,Frankie Fire Mutual Aid,CH-3,FM
CSV file formats are useful for exchanging data between systems and spreadsheets.