→ Alcohol compounds: An alcohol contains one or more hydroxyl (OH) group(s) directly attached to carbon atom(s), of an aliphatic system. For example, CH3OH.
→ Phenol compounds: A phenol contains one or more hydroxyl (OH) group(s) directly attached to carbon atom(s), of an aromatic system. For example, C6H5OH
→ Alcohol compounds: The substitution of a hydrogen atom in a hydrocarbon by an alkoxy or aryloxy group (R-O/Ar-O) yields another class of compounds known as 'ethers', for example, dimethyl ether (CH3OCH3).
→ In short, ether is a compound which is formed by substituting the hydrogen atom of hydroxyl group of an alcohol or phenol by an alkyl or aryl group.