Oracle Database 11g Standard Editon description from oracle.com portal:
Affordable, Full-Featured Database
Oracle Database 11g Standard Edition is an affordable, full-featured database for servers with up to four sockets. It includes Oracle Real Application Clusters for higher availability, provides enterprise-class performance and security, is simple to manage, and can easily scale as demand increases. It is also upwardly compatible with Enterprise edition and can easily grow with you, protecting your initial investment.
- At $350 per user minimum 5 users), save money by buying only what you need today, and scale out as your demand changes with Real Application Clusters
- Improve Quality of Service with enterprise-class performance, security and availability
- Run on Windows, Linux, and Unix operating systems and easily manage with automated, self-managing capabilities
- Streamline application development with Oracle Application Express, Oracle SQL Developer and Oracle Data Access Components for Windows