In the book of 'Lasers in Dermatology: Parameters and Choice,' specific laser parameters are described around each laser instrument for these novices. However, since it is impossible to treat effective and safe laser simply by memorizing parameters, it is described based on the important principles that is essential for parameter control. This book describes a total of 13 lasers and energy-based devices : Q-switched ruby laser, Q-switched Nd:YAG laser, picosecond alexandrite laser, long-pulsed Nd:YAG laser, pulsed-dye laser, intense pulsed light (IPL), long-pulsed alexandrite laser, Er:YAG laser, CO2 fractional laser, fractional microneedle radiofrequency (RF), light-emitting diode (LED), skin equipment, and 1,450nm diode laser. And for novices, it explains the simple principles of lasers and the concepts you need to know when you start skin care and laser. It also explains the treatment of scars and melasma, which are the diseases that novices are most interested in. Finally, it describes post-inflammatory (PIH) and side effects and complications that novices are embarrassed about in diagnosis and treatment.