$(a)$ Define evaporation. Out of nylon and cotton clothes,which will be more comfortable during summer and why?
$(b)$ Are evaporation and boiling the same? If not,then why?

(N/A) Evaporation: The phenomenon of change of a liquid into vapours at any temperature below its boiling point is called evaporation. Cotton is a better absorber of water than nylon. During summer,cotton clothes absorb sweat,which upon evaporation causes cooling of the body.
$(b)$ No,they are not the same. Boiling is a bulk phenomenon that occurs at a specific temperature called the boiling point. In contrast,evaporation is a surface phenomenon that can occur at any temperature below the boiling point.