Ultra-fast spectroscopic techniques provide invaluable information in understanding complex surface phenomena. Many ultra-fast techniques including vibrational sum frequency generation (SFG) are developing in a rapid pace, however very little academic literature exists on how to best utilize this novel techniques towards real life applications. Complex nature due to heavy mathematics involvement has limited the use of available books only to the scientists in the field. This book therefore, provides new simplified approaches in understanding, developing, and applying SFG spectroscopy to extract surface specific information. The book should help anyone who may be interested in understanding and utilizing SFG technique for studying surfaces both in life and material sciences.