Linked from
The 7 pages that link to Williamson ether synthesis, each with the reason it gives.
EtherRelated: It is a broadly useful route for constructing unsymmetrical ethers.
SN2 reactionBroader topic: It uses SN2 bond formation to connect an oxygen atom to an alkyl group.
Sodium hydrideRelated: Sodium hydride can generate the alkoxide nucleophile from an alcohol.
Potassium hydrideRelated: KH can generate the alkoxide nucleophile used in this synthesis.