If your company has a single database, in a single server, and you never need to receive data from other systems or send data to other servers, you could skip this chapter.
Many systems receive their data through direct user input. However, there are some cases where transferring data is important:
You want to migrate to a new system and you want to populate the new database with data coming from your old system.
Your accounting system works in a mainframe and you do not want to change this system. However, it would be useful to have some accounting information in the SQL Server Sales database. In this case, you must periodically refresh this information from the mainframe.
The post office changes the national postal ...