Normalization is the process of reducing data redundancy and improve quality of the data, the way to achieve this is using keys (primary and foreign) and relationships between them. 1NF 2NF and 3NF (normalization Form) are used to achieve this
RDBMS acronym for Relational Database Management System, it is a software that implement the management of an organized collection of data (or database) and also implements the relational model. SQL Server, Oracle, Sybase are examples of RDBMS.
SQL acronym for Structured Query Language is a standard language used in RDBMS based on set theory (database) and predicate logic (relational model)
T-SQL or Transact SQL is the Microsoft implementation of SQL used in SQL Server products.
Null is the RDBMS implementation for the lack of data, and meet the following requirements: is not data type dependant, and logically evaluates to undetermined, it is not equivalent to an empty string and is not equivalent to numeric 0.