1.2 How MySQL AB Operates

It might seem odd for a certification exam to require you to know about the company behind the product. However, MySQL AB is a company that does things differently, and in order to understand how licenses work and how to make use of MySQL most effectively, knowledge of how the company operates is considered essential for anyone working with the products provided by the company.

To understand MySQL AB's business model, it's important to realize that all the software MySQL AB creates is distributed using one of two licenses:

• The GNU General Public License (GPL), which allows anyone to use the software without restrictions provided they either do not redistribute the software or that they redistribute the software under the same license. Usage of MySQL under the GPL comes at no cost.

• A Commercial License, which allows the license holder to redistribute the software in a less restricted manner. Commercial licenses must be paid for, but are relatively inexpensive.

Section 1.4, "MySQL Dual Licensing," covers the different license types in greater detail. The largest number of installations of MySQL are used under the GPL.

In addition to selling commercial licenses, MySQL AB also provides professional services, such as the following:

• Selling support services to companies that use MySQL. Companies purchase these ser-vices as insurance to make sure that they have a MySQL developer available if needed.

• Selling consulting services to companies that have a need for assistance outside the scope provided by the support services.

• Selling training services to companies and individuals who want to gain a better understanding of the MySQL products.