Main article: IUPAC nomenclature of organic chemistryVarious names and depictions for one organic compound.

Hello student.
I am not able to interpret your questions.
If you are asking about that why there are different names for same compound in chemistry the answer is, there are two systems of naming used in chemistry the first one is IUPAC system while the other one is trivial or common name system. Many of the organic compounds have their general or common name .
For example, The IUPAC name of CH3COOH is ethanoic acid while its common name is Acetic acid. Similarly Methyl benzene is also known as toluene .Methanoic acid is known as formic acid also.
If you want to gain in depth knowledge of IUPAC naming of organic compounds you can refer to our study material on following link
http://www.askiitians.com/iit-jee-chemistry/organic-chemistry/iupac-and-goc/nomenclature-of-organic-compounds.aspx

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