. PostgreSQL is a Object-Relational Database Management System (ORDBMS) developed in the year 1996.
    . It can handle data ranging from a single machine applications to internet based applications.
    . Available in Windows, Linux, MacOS, Unix, Solaris etc.
    . Many companies like Apple, Red Hat, Cisco etc uses this database.

  Downloading PostgreSQL:

     . PostgreSQL database is free. We can download from postgresql website.

     . Select the Operating System.
     . Download the Installer.

     . Now choose the version of the database and also the OS version. Click on download.

  Installing PostgreSQL:

     . Run the setup file. Click on Next.

     . Give the Password to connect to the database.

  Using GUI tool to connect PostgreSQL:

     . We can connect to the database and perform operations like storing, retrieving data either from command prompt or from pgAdmin4 which is GUI.
     . Search for pgAdmin in the start menu.

     . Now connect to the database as follows:

     . Type the password and click on OK.

    Creating database:

          . Right click on Databases > Create > Database.
          . Give Database name and click on Save.

    Creating Table:

          . Right click on Tables > Create > Table.

          . Give the table name and add the columns as below:

          . In the columns tab, click on the + sign.

          . We can add the columns by specifying column name, data type and constraints as well. Finally click on Save.

    Inserting data:

          . We can insert data into the table using scripts.
          . Right click on table > Scripts > Insert Script.

          . It opens the SQL query tab where you can insert the values and click on Run button.

   Retrieving data:

         . We can write SELECT query in the query tool or else we can use the scripts.
         . Right click on the table > Scripts > SELECT Script
          . Run the query, we get the resultset of the table as follows:

   Updating data:

        . We can update record using query in the query tool or by using Scripts.
        . Right click on table > Scripts > UPDATE Script.
          . We have to modify the query as required and run it.
          . We can observe data is updated by using select query to retrieve data.

   Deleting record:

          . We can delete record from the table by using script as follows:
          . Right click on table > Scripts > DELETE Script.
          . We have to modify the query as the way we wanted to delete the records.
          . We can observe record is deleted.