Question

what is sublimation?

Answer 1

Sublimation is an endothermic process that occurs at temperatures and pressures below a substance's triple point in its phase diagram, which corresponds to the lowest pressure at which the substance can exist as a liquid. 

Answer 2

$\textbf{Sublimation}$

Sublimation can be defined as the process by which a solid directly changes its solid state to vapour without passing through the liquid state and vice versa is called sublimation.

Substances which can sublime are :

Naphtaline balls, Camphor, etc.