BTEQ is an abbreviation of Basic Teradata Query, which is a general-purpose, command based program that allows users on a workstation to communicate with one or more Teradata Database systems, and to format reports for both print and screen output. Using BTEQ you can submit SQL queries to Teradata Database. BTEQ formats the results and returns them to the screen, a file, or to a designated printer.
Teradata BTEQ documentation:
http://developer.teradata.com/sites/all/files/documentation/linked_docs/2414020A_BTEQ-Reference-13.10.pdf