The main volcanological concept is shown and expressed so that any volcano can be understood easily. Volcanic products are listed and explained in plain language from lava flow to various pyroclastic products. The volcanic products have been explained schematically and their textural, field relationships characteristics are highlighted. The origin of magma within the interior of the Earth is also explained and the link between mantle and crust has been shown. The relationship among crust, mantle, and core has been highlighted embracing the source-to-surface model. An updated explanation of the Pyroclastic Density Currents (PDC) has been done to perceive their danger. Some of the most successful Volcanology books have been used. This will help the students, with a passion for Volcanology, to understand the principles of Volcanology.