Solar Flares refer to solar coronal mass ejections (CME), also known as geomagnetic storms. Solar flares are an important part of solar activity, associated with rapid and intense energy release in active regions of the solar atmosphere. In this book, Chapter One discusses the origin of solar flares and their threat to our civilization. Chapter Two presents a study of time and space variations of electron density characteristics during a solar X-ray flare influence. Chapter Three provides an analysis of the ionospheric D-region disturbances in response to the effects of solar X-ray flares. Chapter Four updates an analysis from January 2011 through July 2016 and discusses whether new research sheds any light on the ongoing Cycle 24 unusual structure and on its future. Chapter Five explores the latest news on zebra patterns in solar radio emissions.