Dictionary makers apply two basic philosophies to the defining of words: "prescriptive" or "descriptive". Noah Webster, intent on forging a distinct identity for the American language, altered spellings and accentuated differences in meaning and pronunciation of some words. This is why American English now uses the spelling "color" while the rest of the English-speaking world prefers "colour". (Similarly, British English subsequently underwent a few spelling changes that did not affect American English; see further at American and British English spelling differences.) Large 20th-century dictionaries such as the "ऑक्सफर्ड इंग्लिश डिक्शनरी" (OED) and Webster's Third are descriptive, and attempt to describe the actual use of words.
While descriptivists argue that prescriptivism is an unnatural attempt to dictate usage or curtail change, prescriptivists argue that to indiscriminately document "improper" or "inferior" usages sanctions those usages by default and causes language to "deteriorate". Although the debate can become very heated, only a small number of controversial words are usually affected. But the softening of usage notations, from the previous edition, for two words, "ain't" and "regardless," out of over 450,000 in Webster's Third in 1961, was enough to provoke outrage among many with prescriptivist leanings, who branded the dictionary as "permissive."

The prescriptive/descriptive issue has been given so much consideration in modern times that most dictionaries of English apply the descriptive method to definitions, while additionally informing readers of attitudes which may influence their choices on words often considered vulgar, offensive, erroneous, or easily confused. "Merriam-Webster" is subtle, only adding italicized notations such as, "sometimes offensive" or "nonstand" (nonstandard.) "American Heritage" goes further, discussing issues separately in numerous "usage notes." "Encarta" provides similar notes, but is more prescriptive, offering warnings and admonitions against the use of certain words considered by many to be offensive or illiterate, such as, "an offensive term for..." or "a taboo term meaning..."

Because of the broad use of dictionaries, and their acceptance by many as language authorities, their treatment of the language does affect usage to some degree, even the most descriptive dictionaries providing conservative continuity. In the long run, however, usage primarily determines the meanings of words in English, and the language is being changed and created every day. As Jorge Luis Borges says in the prologue to "El otro, el mismo": ""It is often forgotten that (dictionaries) are artificial repositories, put together well after the languages they define. The roots of language are irrational and of a magical nature.""

Lexicography
Character dictionaries
प्रकार
Prescription and description