(N/A) Alcohols and phenols are formed by the replacement of a hydrogen atom in an aliphatic and aromatic hydrocarbon,respectively. Ethers are formed by the replacement of a hydrogen atom in a hydrocarbon by alkoxy or aryloxy groups. Ethers can also be visualized as the replacement of the hydrogen atom of the $-OH$ group of an alcohol or phenol by an alkyl or aryl group.
Alcohols contain one or more $-OH$ groups bonded directly to carbon atom$(s)$ of an aliphatic system (e.g.,$CH_3OH$),whereas phenols contain $-OH$ group$(s)$ bonded directly to the $sp^2$ carbon of an aromatic system (e.g.,$C_6H_5OH$).
Applications:
$1$. Ethanol is used as a solvent for polishing wooden furniture and is commonly known as spirit.
$2$. Many essential compounds in our daily life,such as the sugar we consume,the cotton used in fabrics,and the paper used for writing,are composed of molecules containing multiple $-OH$ groups.
$3$. Ethers,such as diethyl ether,are widely used as solvents in laboratories and in the extraction of organic compounds.