Question

What are diathermic and adiabatic containers?

Answer 1

Diathermic wall allows the transmission of heat through it, for example, metals.
The adiabatic walls are those which don't allow the heat flowing through them, example, the walls of thermos flask.

Answer 2

diathermic are the substances that allows heat to go through it such as glass of car. Adiabatic is the substances that wont allow heat through it is called adiabatic