A data source (sometimes called a data file) is as simple as it sounds: a place where data is taken from. The source can be any type of data in any file format, as long as the program knows how to read it.
Multiple applications can use a data source, including database applications like Microsoft Access, MS Excel and other spreadsheet programs, word processors like Microsoft Word, your web browser, offline programs, etc. A common scenario when dealing with Microsoft Word using a data source is for Word to do a mail merge from data taken from an Excel document. See our introduction to mail merge for more information.
Important facts about the data source
A data source file used in one program for a single purpose may not have any relevance in a different program, even if both use data source files. In other words, a particular “data source” is subjective to the program using the data.
For example, a data source for a Microsoft Word mail merge might be a CSV file that contains a group of contacts so that they can be automatically typed into a Word document to print envelopes with the correct names and addresses. Such a data source, however, is not very useful in any other context.
Examples of data sources
As mentioned above, a data source, also called a data file, is simply a collection of records that store data. It is this data that is used to populate the merge fields in mail merges. That is why any text file can be used as a data source, be it a plain text file or a real database file.
They can come from programs like MS Access, FileMaker Pro, etc. In theory, any Open Database Connectivity (ODBC) database can be used as a data source. They can also be created in spreadsheets from Excel, Quattro Pro or any other similar program. The data source can even be a simple table in a word processing document.
The idea is that a data source can be any type of document as long as it is organized to provide a structure for the receiving program to extract the data. For example, an address book contact can be used in some scenarios because there is a column for a name, address, email account, and so on.
Another type of data source could be a file that records how many times people check into a doctor’s office. A program can use the data source to aggregate all billing times and display them on a website or use them within a program, either to display content or to interact with some other type of data source.
Other types of data sources can be taken from a live source. The iTunes program, for example, can use a live feed to play Internet radio stations. The feed is the data source and the iTunes app is the one that displays it.