Explain Unsymmetrical ether with an example

Hint: Ethers are a group of chemical compounds named after the Latin term aether, which literally means "to burn." Ether is combustible at ambient temperature and under high pressure. In ether, the oxygen atom is connected to two alkyl or aryl groups, which might be the same or different.

Complete answer:
The general formula of ether is given as $R - O - R$ , $R - O - {R^{'}}$, $R - O - Ar$ or $Ar - O - Ar$ where $R$ represents an alkyl group and $Ar$ represents an aryl group.
Based on the substituent group connected to the oxygen atom, ethers can be divided into two categories: symmetrical ethers and unsymmetrical ethers.
Unsymmetrical ethers are ethers in which the groups $R$ and ${R^{'}}$ are different.
Example:
Ethyl methyl ether - $C{H_3} - O - C{H_2}C{H_3}$
Methyl phenyl ether - ${C_6}{H_5} - O - C{H_3}$
Benzyl phenyl ether - ${C_6}{H_5} - O - C{H_2}{C_6}{H_5}$

Additional Information:
At low temperatures, dimethyl ether is employed as a refrigerant and a solvent. Diethyl ether is a common ingredient in surgery anaesthetic. As a motor fuel, ether is mixed with gasoline. Diethyl ether is a common solvent for oils, gums, resins, and other similar materials. Because of its high boiling point, phenyl ether is useful as a heat transfer medium.

Note:
Ether structure is similar to that of the structure of the alcohol. Both the structures of ether and alcohol are similar to the structure of water molecules. This is because, in alcohol, one hydrogen atom of a water molecule is replaced by an alkyl group and in case of ethers, both hydrogen atoms of water molecules are replaced by alkyl or aryl groups.