At the CrossFit Level 1 seminars, three overhead movements are taught together: The press, the push press, and the push jerk. All three take a barbell (or other object) from the shoulders to locked out overhead. The difference is in the use of the hip.
In this Part 1 The Press, Adrian Bozman explains the basics of performing the press correctly, including the role of midline stability. In this video, the press is taught primarily as a skill transfer exercise for the push press and the push jerk, which are much more athletic movements with significantly higher power generation. They are described in Part 2 The Push Press and Part 3 The Push Jerk.
The video was captured at the CrossFit Level 1 Certification Seminar in Golden, CO on October 24, 2008. Chris Spealler is the demogirl.