Normalization is a process of removing redundancy from the
tables.

De-normalization is  introducing redundancy.

Normalization is the process of organizing data in a 
database. This includes creating tables and establishing 
relationships between those tables according to rules 
designed both to protect the data and to make the database 
more flexible by eliminating two factors: redundancy and 
inconsistent dependency.

Normalization - is the process of desing of the datamodel 
and effocential storre the data in database

Normalization is the process of decomposition of complex 
data in to simple way.
Denormalization is vice versa.

In relational database design, the process of organizing
data to minimize redundancy. Normalization usually involves
dividing a database into two or more tables and defining
relationships between the tables. The objective is to
isolate data so that additions, deletions, and modifications
of a field can be made in just one table and then propagated
through the rest of the database via the defined relationships. 

De-normalization is  introducing redundancy.