GPGeorge pointed you in the right direction, but if you wanted to look up by the correct phrase, it is MAIL MERGE. Here are a couple of links that come from two different directions.
Describes how to use the Mail Merge feature in Word to create and to print form letters that use the data from an Excel worksheet.
support.microsoft.com
Describes that how to automate Word with Visual Basic to create a Mail Merge.
learn.microsoft.com