Sublimation is the state of conversion of solid to directly gas without changing into liquid state first. It is also vice versa meaning true for opposite. Change of state from gas to solid without changing into liquid.
It's three examples are- Naphthalene balls, carbon dioxide gas and camphor. Carbon dioxide sublimes from gas to solid as dry ice and solid to gas. While, Naphthalene balls and camphor can convert from solid to gas directly without going through/ changing into liquid state first.