Speaking the same language is important in any project or company. Making sure everyone is clear on the terms or lingo in your group is especially important. For example, if you are talking about a build process or bug to someone on your team and do not define the context, or if the terms are not explicitly defined somewhere, you'll miscommunicate your point or vice versa. This can lead to project setbacks.
In the following chapters, I will continue to define terms that we use at Microsoft and what seem to be industry standard terms. This is important because there can be variations of a definition, and I want to make sure we are all clear on the points being made. Also, it is the build team's responsibility to set these definitions for a group and publish them on an internal Web site so that no one's confused about what they mean and people who are unfamiliar with the terms can reference them easily.