The isomerism shown by $n$-butyl alcohol and isobutyl alcohol is

Functional isomerism is exhibited by the following pair of compounds:

Explain the following terms:
$(a)$ Isomerism
$(b)$ Position isomerism
$(c)$ Chain isomerism
$(d)$ Functional group isomerism
$(e)$ Metamerism
$(f)$ Optical isomerism

Which isomerism is exhibited by the functional group diethylamine?

How many isomers are possible for the formula $C_2BrClF_4$?

Esters are functional isomers of: