Acronym vs. Abbreviation vs. Initialism

Last Updated:

Acronym or Abbreviation?

You’re guaranteed to have heard of acronyms and abbreviations before.

You’ve certainly heard examples of both acronyms and abbreviations.

And if you were given a test with 10 acronyms and abbreviations on it and had to correctly determine which was an abbreviation and which was an acronym, you would probably get some of them correct.

But do you really know what the difference is between acronyms and abbreviations?

The real reason you may be confused about the difference between abbreviations and acronyms is because others are too. When you hear everyone use them interchangeably, it makes it really confusing!

Oh, and what about initialisms?

Table of Contents

Abbreviations

An abbreviation is a shortened form of one or more words.

Abbreviation Examples

  • Ave. = Avenue
  • St. = Street
  • Jan. = January
  • In. = Inches
  • vs. = versus
  • ID = identification or identifier
Photograph of two street signs using the abbreviations Ave for avenue and St for street.
Two street signs using the abbreviations Ave for avenue and St for street.

Acronyms

  • Shortened form of multiple words
  • Pronounced as a word
  • Does not have to be upper case
  • Does not need to take a letter from each word

An acronym is a shortened form of multiple words that itself is a word. Acronyms are pronounced as words.

Note that an acronym does not need to take a letter from each word. It also does not need to be upper case.

Are acronyms always capitalized?

No, not all acronyms are capitalized. While some acronyms like NASA or PIN are capitalized, others like scuba or radar are not. Note that they are all still pronounced as words, though.

Photograph of a the space shuttle Atlantis before takeoff. NASA is an acronym that stands for National Aeronautics and Space Administration.
NASA is an acronym that stands for National Aeronautics and Space Administration.

Acronym Examples

  • AIDS = Acquired Immune Deficiency Syndrome
  • laser = Light Amplification by Stimulated Emission of Radiation
  • NASA = National Aeronautics and Space Administration
  • NATO = North Atlantic Treaty Organization
  • PIN = Personal Identification Number
  • radar = RAdio Detection And Ranging
  • scuba = Self-Contained Underwater Breathing Apparatus
  • SIM (card) = Subscriber Identification Module
  • taser = Thomas A. Swift’s Electric Rifle
  • ZIP (code) = Zone Improvement Plan

Initialisms

An initialism is a series of letters formed by each of the first letters in a series of words. Many acronyms are also initialisms, but not all initialisms are acronyms.

Photograph of an ATM (automated teller machine).
ATM is an initialism that stands for automated teller machine.

Initialism Examples

Here are some initialisms that are not acronyms:

  • ATM = Automated Teller Machine
  • CEO = Chief Executive Officer
  • CIA = Central Intelligence Agency
  • EU = European Union
  • FAQ = Frequently Asked Questions
  • FBI = Federal Bureau of Investigation
  • FYI = For Your Information
  • IDK = I Don’t Know
  • NFL = National Football League
  • OMG = Oh My God
  • TBH = To Be Honest
  • UFO = Unidentified Flying Object
  • WHO = World Health Organization

And here are some initialisms that are also acronyms:

  • NASA = National Aeronautics and Space Administration
  • PIN = Personal Identification Number
  • ZIP = zone improvement plan

Controversy

So is the above information correct? It depends on who you ask…

Some dictionaries and style guides agree that acronyms must be pronounced as words, while others consider all initialisms to also be acronyms.

Summary

Abbreviations

  • Shortened form of one or more words

Acronyms

  • Shortened form of multiple words
  • Pronounced as a word

Initialisms

  • Shortened form of multiple words
  • Formed by the first letters in a series of words
  • May also be considered an acronym if it is pronounced like a word

Hopefully that helps you better understand the difference between acronyms, abbreviations and initialisms.

Most Popular Slang