TERADATA is a Database server which can handle multiple clients concurrently. Teradata is a RDBMS (Relational Database Management System) which is strongly recommended for handling huge data warehouse environment. The unique feature of Teradata is its parallel architecture which is a core part of this RDBMS. It is rightly said that TERADATA is born to be parallel. Teradata in a basic language can be considered as a RDBMS just like Oracle etc which is used to maintain Data Warehouse of big enterprises. However, the core architecture and the utilities provided by Teradata makes it an obvious choice for handling most complex Data Warehousing environments.
TERADATA is a Database server. Like other Databases available in the market, it also follows ANSI standards. However TERADATA has it's own standards and some specific utilities which make it more fun to work on. Understanding Teradata Architecture is very important as it helps one to write better SQL queries with the help of Explain Plan and other helpful utilities. For time being, understand that Teradata is a RDBMS with its own standard and utilities along with standard ANSI.