On August 12, millions of people across Greenland, Iceland and Spain shall witness a total solar eclipse. There are four different types of solar eclipses, including total solar eclipse, annual solar eclipse, partial solar eclipse, and hybrid solar eclipse. Partial solar eclipse is the most common type of solar eclipse. A hybrid solar eclipse — the rarest type of solar eclipse — is witnessed when an eclipse shifts between annular and total as the shadow of the Moon moves across the globe. In this case, some parts of the world see a total solar eclipse, while others observe an annular solar eclipse.