An abbreviation and an acronym are both shortened versions of[/color][color=#000000][/font][font=Lucida Sans Unicode] something else. Both can often be represented as a series of letters. Many people are unable to tell the difference between an abbreviation and an acronym.

Abbreviation vs. Acronym
There is a great deal of overlap between abbreviations and acronyms. Every acronym is an abbreviation because the acronym is a shortened form of a word or phrase. However, not every abbreviation is an acronym, since some abbreviations - those made from words - are not new words formed from the first few letters of a series of words.

Abbreviation

An abbreviation is a shortened form of a word or phrase, as N.Y. for New York, Mr. for Mister, lb for pound or ctn for carton.

There are millions of common abbreviations used every day.

When you write out your address, most people write "St. or Ave." instead of "street" or "avenue."
When you write the date, you may abbreviate both the day of the week (Mon, Tues., Wed., Thurs., Fri., Sat., and Sun.) and the month of the year (Jan., Feb., Aug., Sept., Oct., Nov., Dec.).
There are also tons of industry specific abbreviations that you may be unaware of unless you are in the industry, such as medical abbreviations or dental abbreviations.
Shortening the word "Avenue" to "Ave." is an abbreviation, because it is the shortened version of the word. However, it is not an acronym since the word AVE is not a new word comprised of the first few letters of a phrase.

Acronym

An acronym, technically, must spell out another word. However, this rule isn't always rigidly enforced:

ASAP is an acronym although the word "asap" is not in many dictionaries. Still, the first letters of each of the words "As Soon As Possible" are used to form the acronym ASAP.
NY is the acronym for New York. Since this acronym is a shortened version of the phrase, by definition the acronym is also an abbreviation.
Like abbreviations, acronyms are used daily, and most people can interpret the meaning of common acroynms without much thought. For example:

You go to the ATM instead of to the automatic teller machine
You give your time zone as EST, CST or PST instead of as Eastern Standard Time, Central Standard Time or Pacific Standard Time.
You use words like BRB (be right back), LOL (laughing out loud), and ROFL (rolling on floor laughing) when texting. These new acronyms were derived from computer lingo. All of these new acronyms are also abbreviations because they are all shortened versions of phrases that IM-ers were using frequently.
Abbreviations and acronyms are shortened versions of words and phrases to speed up our communication. Be sure to use them correctly - since, a misuse can lead to a big miscommunication.


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