PostgreSQL

PostgreSQL is an object-relational database management system (ORDBMS) based on POSTGRES, Version 4.2, developed at the University of California at Berkeley Computer Science Department. PostgreSQL is an open-source descendant of this original Berkeley code and now developed by many programmers all over the world connected via the Internet.

PostgreSQL execute various tasks via cooperation of two independant processes,i.e.,server and client.

server

A server is an application program that accepts connections from a client in order to service requests by sending back responses.

client

A client is an application that accesses a remote service on another computer system, known as a server, by way of a network. tkDerm as a client translates users' request to SQL language, which is sent to and processed by a PostgreSQL server. The processed result is sent back to tkDerm, which displays the response in such a way that is understood easily by users.