This book starts at an introductory level and leads reader to the most advanced topics in fluorescence imaging and super-resolution techniques that have enabled new developments such as nanobioimaging, multiphoton microscopy, nanometrology and nanosensors. The interdisciplinary subject of fluorescence microscopy and imaging requires complete knowledge of imaging optics and molecular physics. So, this book approaches the subject by introducing optical imaging concepts before going in more depth about advanced imaging systems and their applications. Additionally, molecular orbital theory is the important basis to present molecular physics and gain a complete understanding of light-matter interaction at the geometrical focus. The two disciplines have some overlap since light controls the molecular states of molecules and conversely, molecular states control the emitted light. These two mechanisms together determine essential imaging factors such as, molecular cross-section, Stoke shift, emission and absorption spectra, quantum yield, signal-to-noise ratio, Forster resonance energy transfer (FRET), fluorescence recovery after photobleaching (FRAP) and fluorescence lifetime. These factors form the basis of many fluorescence based devices. The book is organized into two parts. The first part deals with basics of imaging optics and its applications. The advanced part takes care of several imaging techniques and related instrumentation that are developed in the last decade pointing towards far-field diffraction unlimited imaging.