A service pack is a software package that contains several updates for an application or operating system. Individual updates are typically called software updates or patches. When a software company has developed several updates to a certain program or operating system, the company may release all the updates together in a service pack.
Many Windows users are familiar with service packs because of the popular service pack released for Windows XP, called SP2. Windows XP SP2 not only included typical updates such as bug fixes and security updates, it added new features. Some of the features included new security tools, interface enhancements to Internet Explorer and Outlook Express, and new DirectX technologies. In fact the SP2 service pack for Windows XP was so comprehensive, many newer Windows programs require it in order to run.
Service packs are usually offered as free downloads from the software developer's website. A software update program on your computer may even prompt you to download a service pack when it becomes available. Typically, it is a good idea to download and install new service packs. However, is may also be wise to wait a week or two after the service pack is released to make sure no new bugs or incompatibilities are introduced with the service pack. If you do not have a high-speed Internet connection, you can often purchase a service pack update CD for a small charge.
While service packs are commonly released for Microsoft products, not all companies use them. Apple's Mac OS X, for example, uses the Software Update program to install incremental updates to the operating system. Each Mac OS X update includes several small updates to the operating system and bundled applications, much like a service pack.