What is the difference between distillation,distillation under reduced pressure,and steam distillation?

At what temperature and pressure does a liquid vaporize in steam distillation?

Which method is used to purify liquids having very high boiling points and liquids which decompose at or below their boiling point?

$A$ liquid with a high boiling point decomposes on simple distillation,but it can be steam distilled for its purification. Explain how this is possible.

Given below are two statements: One is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Thin layer chromatography is an adsorption chromatography.
Reason $R$: $A$ thin layer of silica gel is spread over a glass plate of suitable size in thin layer chromatography which acts as an adsorbent.
In the light of the above statements,choose the correct answer from the options given below.

Which of the following organic compounds could not be dried by anhydrous $CaCl_{2}$?