Connection pooling is conceptually similar to any other form 
of object pooling. Database connections are often expensive to 
create because of the overhead of establishing a network 
connection and initializing a database connection session. In 
turn, connection session initialization often requires time 
consuming processing to perform user authentication, establish 
transactional contexts and establish other aspects of the 
session that are required for subsequent database usage. 
Hence, sharing of connection object helps to both alleviate 
connection management overhead and decrease development tasks 
for data access. The sharing and storing mechanism of 
connection object is known as connection pooling.