1.) Oracle is made up of a set of processes running in your operating system. These processes manage how data is stored and how it is accessed. I will cover these processes in detail in the future; but for now we just need to understand that Oracle is a program that is running in the background, maintaining your data for you and figuring out where it should go on your hard drive.
In almost all relational databases, data is accessed through SQL, or Structured Query Language, and Oracle is no exception. SQL allows you to SELECT your data, INSERT new records, UPDATE existing records and DELETE records you want to get rid of. SQL can be embedded in other languages or you can run scripts of SQL directly against the database.
2. ) Based in Redwood, California, Oracle Corporation is the largest software company whose primary business is database products. Historically, Oracle has targeted high-end workstations and minicomputers as the server platforms to run its database systems. Its relational database was the first to support the SQL language, which has since become the industry standard.
Along with Sun Microsystems, Oracle has been one of the leading champions of network computers.
Some of Oracle's tools to access the database and create programs are:
SQL*Plus
It has a command line interface. With it, you can access the database and write stored procedures, you can run SQL commands to retrieve data and you can run scripts of either SQL, PL/SQL or built-in SQL*Plus commands, or a mixture of those three things.
Oracle Developer
It is a 4GL GUI application Builder. With Developer, you can create forms, reports, and graphics. Oracle*Forms and Oracle*Reports are two components of Oracle Developer. Earlier versions created client-server applications, but the more recent versions create web applications that run under the Oracle Application Server (OAS). OAS is a web-based application server sold by Oracle. OAS is licensed separately and is very expensive (as are its closed source competitors). The current version is OAS 10g.