Chapter 1 is an introduction to the subject, including historical survey, technological, experimental and theoretical aspects, processing, assessment, and interpretation of optical data. The basic principles of remote sensing are outlined as a powerful tool for explorations of ocean environment. Remote sensing is defined as a scientific technology of data acquisition, based on fundamental principles of electromagnetic radiation. The successful implementation of remote sensing for geophysical and/or military purposes requires the development of a full-scale physics-based methodology and high level of competence in the field of information technology and management. From this point of view, remote sensing can be perceived as an art of cognition. The introduction contains four sections titled “Definition and Objectives,” “Physics and Techniques of Optical Remote Sensing,” “Optical Oceanography: State of Science,” and “Optical Data Acquisition and Analysis.” Modern space-based optical systems enable the measurement of a very diverse range of scales—from several dozen cm to hundreds of km; therefore, such fundamental properties of the ocean surface as variability, scaling, and self-similarity, can be explored and monitored on a regular basis. Advanced satellite observations can provide sophisticated information creating technological breakthrough in geosciences, remote sensing, and applied physics. Some state-of-the-art developments are reported and discussed in other chapters of the book. These materials may help the reader to better understand optical remote sensing capabilities. An extended bibliography provides comprehensive information and details.