What is the differences between ABAP and OOABAP. In which situation we use OOABAP? 

End of the selection event is mostly used when we are writing HR-ABAP code. In the HR-ABAP code, data is retrieved in the start of selection event and printing on the list and all will be done at the end of the selection event.

To format the ABAP code 'pretty printer' is used.

Webdynpro for ABAP is SAP web interface model which is used to develop web applications in SAP.

The difference between the table and template is that, table is a dynamic and template is a static.

SE01 is the main screen of the Change and transport Organizer. From here the administrator can acheive all tasks related to transport requests - such as create, change, view logs, display client/delivery transports, etc. SE09 and SE10 can also be accessed from here. However, not all developers might be granted access to this transaction.

SE09 is the workbench transport requests transaction - here the developers can track changes to all ABAP workbench objects (dictionary, reports, module pools, etc). This is a developer-specific transaction and mostly all developers have access to this transaction.

SE10 is the customizing request display transaction - this displays all the customizing requests in the system. Again, this could be restricted to Business analysts if required, since they would be doing most of the customizing changes in the system.

The Change and Transport System (CTS) is a tool that helps you to organize development projects in the ABAP Workbench and in Customizing, and then transport the changes between the SAP Systems and clients in your system landscape. This documentation provides you with an overview of how to manage changes with the CTS and essential information on setting up your system and client landscape and deciding on a transport strategy. Read and follow this documentation when planning your development project.

Transparent tables: Transparent tables in the dictionary has a one-to-one relation with the table in database. Its structure corresponds to single database field. Table in the database has the same name as in the dictionary. Transparent table holds application data.

Pooled tables: Pooled tables in the dictionary has a many-to-one relation with the table in database. Table in the database has the different name as in the dictionary. Pooled table are stored in table pool at the database level.