Article: This can be a spreadsheet file, database file, or even a text document with the proper formatting. Spreadsheet files are most commonly used; this guide assumes you are using a spreadsheet.  Your data file should have all the information that will have to change from copy to copy. For example, if you're writing a form letter, your data file will hold the names and possibly the addresses of everyone you intend to send the letter to. Put one item of information in each cell along a line, so that each type of information (first name, last name, honorific, and so on) is in its own column.  Make sensible column names. Mail merge reads data in columns. It will assume that the first entry in each column of information is the general name for that type of information, so use names that make sense for you. For example, start a column of first names by typing “firstname,” then put all the first names below it. When you are asked which field to insert into your letter, you will see “firstname” as an option and remember what is contained in that column.  Microsoft Office users who also use Outlook for their e-mail can use their Outlook address book as a data file instead, if desired. Save it somewhere you can find it easily, and name it something you will easily remember. This is the document you will be inserting information into. For example, if you're writing a form letter, the primary document is the letter. Any item that mail merge will fill in for you (such as names) should be left blank for now.

What is a summary?
Build a data file. Save the data file. Write out your primary document.