Explain the classification of haloalkanes and haloarenes on the basis of the number of halogen atoms with examples.

(N/A) Haloalkanes and haloarenes are classified as mono-,di-,or polyhalogen (tri-,tetra-,etc.) compounds depending on the number of halogen atoms present in their structure.
$1$. Monohalogen compounds: These contain only one halogen atom. Examples include $C_2H_5-X$ (monohaloalkane) and chlorobenzene (monohaloarene).
$2$. Dihalogen compounds: These contain two halogen atoms. Examples include $CH_2(X)-CH_2(X)$ (dihaloalkane) and $1,2-$dichlorobenzene (dihaloarene).
$3$. Trihalogen compounds: These contain three halogen atoms. Examples include $CH_2(X)-CH(X)-CH_2(X)$ (trihaloalkane) and $1,2,3-$trichlorobenzene (trihaloarene).