How do you name ethers, esters, and nitriles? Which IUPAC naming method is right?

Hint: Chemical compounds are classified into different types based on the functional groups. Ethers are the chemical compounds in the form of $ ROR $ . Esters are the chemical compounds in the form of $ RCOOR $ . Nitriles are the chemical compounds containing a $ - CN $ group attached to an alkyl group.

Complete answer:
Ethers are the chemical compounds consisting of carbon, oxygen and hydrogen atoms. Ethers are in the form of $ ROR $ in which the two alkyl groups are bonded to oxygen atoms. The IUPAC naming of ethers can be written as alkoxy alkane or alkyl alkyl ether.
Let us consider $ C{H_3}O{C_2}{H_5} $ . It can be written in two different ways as $ 1 $ -methoxy ethane and ethyl methyl ether.
Esters are the chemical compounds consisting of carbon, oxygen and hydrogen atoms. Esters are in the form of $ RCOOR $ . The IUPAC naming of esters can be written as alkyl alkanoate.
Let us consider $ C{H_3}COO{C_2}{H_5} $ the IUPAC name will be ethyl methanoate.
Nitriles are also known as cyanides in which the alkyl group is bonded to the carbon atom in cyanide. The IUPAC naming of cyanides can be written in two different ways as alkene nitrile and alkyl cyanide.
Let us consider $ C{H_3}C{H_2}C \equiv N $ in can be named as propene nitrile and ethyl cyanide.

Note:
While writing ethers as alkyl alkyl ethers, the group which comes first in alphabetical order must be written first. When ethyl and methyl groups are there, the ethyl group must write first according to alphabetical order. Thus, $ C{H_3}O{C_2}{H_5} $ was named as ethyl methyl ether.