API defines the kinds of calls or requests that can be made, how to make them, the data formats that should be used, the conventions to follow, etc.
A CSV file typically stores tabular data (numbers and text) in plain text, in which case each line will have the same number of fields.
XML standard is a flexible way to create information formats and electronically share structured data via the public Internet, as well as via corporate networks.
In SQL Server the data dictionary is a set of database tables used to store information about a database’s definition.
JSON is a text-based data interchange format designed for transmitting structured data. It is most commonly used for transferring data between web applications and web servers.
A data source, in the context of computer science and computer applications, is the location where data that is being used come from.