CSV stands for Comma-Separated Values, a plain text format used to store tabular data simply.
Each line of the text file represents one row, with fields separated by commas.
The very first line frequently lists the column headers describing the contents of each field.
For example, a file line reading Alice,30,London stores a name, an age, and a city.
Its universal compatibility makes it popular, though it lacks built-in data types and strict schema rules.
Comma-Separated Values remains the most widely supported export format in computing history.
Because it is plain text, almost any software application can read and write CSV files.
You can inspect a CSV file using a simple text editor without specialised database software.
The format is conceptually simple: newlines separate records, and commas separate individual fields.
Problems arise immediately when a text field contains a literal comma inside its value.
To prevent the parser from splitting the field, the value must be wrapped in quotation marks.
If the text also contains quotation marks, they must be escaped by doubling them up.
Different countries use different delimiters, such as semicolons in regions where commas denote decimals.
A fundamental limitation is that CSV files do not store column data types alongside the data.
A parser must guess whether an entry is an integer or a string containing an essential leading zero.
If a spreadsheet guesses integer, it strips the leading zero and corrupts identifiers like phone numbers.
CSV files also lack compression and indexing, making them inefficient for massive datasets.
Large text files consume unnecessary disk space and require full scans to read single values.
Despite these flaws, CSV is the default interchange format for exporting and sharing small datasets.
Always inspect delimiter conventions and quote handling when parsing CSV files from unknown sources.
One question on this card. Every option explains itself once you pick, right or wrong.
14 concepts in this module, then a graded test with every answer explained.