A CSVT file is a single line of text listing the field types used in your CSV file, separated by commas. When adding CSV files to QGIS you may notice all fields are treated as strings (text data); creating a CSVT file will help QGIS recognize the correct field types. Common field types you will come across are: string, for text data; integer, for whole numbers; real (sometimes called double), for numbers with decimals; and boolean, for yes/no or true/false data with only two options. This task sheet will teach you how to manage your comma separated value (CSV) files and improve joins by creating a CSVT file.