The CSV File Format
CSVs are files that contain plain text and numeric data arranged in a spreadsheet.
This format is used to transfer analytic, payment, income, tax or any other details to other information management formats and solutions. It’s supported by Microsoft Excel or LibreOffice (as well as other programs used to open spreadsheets).
These files are good for collecting data. But, if you want to use the information that the spreadsheet contains, it's better if you convert it into PDF format.
You just use data contained in one program for transferring to CSV and then process it in other solutions.
CSV Technical Details
It can also be opened by notepad. But if the document is large, it may not open correctly.
It’s very simple and contains only text, separated by commas, or a long text with strings and lines or some other definite character. It helps files to be easily transferred and transformed into any other format that you need. The technical characteristics of CSV files are good not only for information storage but also can be used to add information to other applications.
For example, you can export contacts by selecting the appropriate format variant.