Possible Duplicate:
What is enterprise software, exactly?
What does “enterprise” means in relation to software architecture?
What makes a component or product "enterprise" software vs non-enterprise ready? Is it difficult to use? Is it support contacts? Is it reputation? Is it a level of testing? Is it integration support? Is it marketing? Is it the focus on the customer of the product?
What makes a piece of software "enterprise" software, rather than something that is for general consumption?
For example, Derby DB is for developers, and small apps, but it's not an "enterprise database".