Three components form the foundation of the rapidly growing field of proteomics research: traditional protein chemistry experiments, separations science, and biological mass spectrometry. The increasing demand for proteomics, as well as the presentation of the 2003 Nobel Prize to John Fenn and Koichi Tanaka for ion source development, has placed biological mass spectrometry in the scientific spotlight. A basic understanding of mass spectrometry is increasingly important for basic, translational, and clinical research. This review article presents an introduction to mass spectrometry, a brief description of different mass spectrometry experiments, and new developments in the field.