abbreviation OR acronym?

Dr - Co. - Ltd - c.o.d - NASA - laser - let's - DVD - radar - a.s.a.p. - etc. - FAQ - HTML - scuba - BBC - DVD - abbrv. - Aids - FBA - NSA - phone - DTRT - telly - Prof. - UK - approx. - don't - PTO

People often ask: "What's the difference between an abbreviation and an acronym?"

To answer this question, we need to understand that an acronym is just one type of abbreviation.

An abbreviation is a short form of a word or phrase. All of the short forms that you see above ↑ are abbreviations.

The four main types of abbreviation are:


A shortening is an abbreviation where the end of the word has been cut off, for example:

shortening full form
app application
ad advertisement
approx. approximately
Co. Company
Prof. Professor


A contraction is an abbreviation where the middle of the word or words has been cut out, for example:

contraction full form
Blvd Boulevard
Dr Doctor
Ltd Limited
ft foot, feet
don't do not


An initialism is an abbreviation made from the initial (first) letters of a group of words. We say the initialism as separate letters, for example:

initialism full form
BA Bachelor of Arts
BBC British Broadcasting Corporation
UN United Nations
DVD digital versatile disc
VIP very important person

Listen to how the initialisms are pronounced, letter by letter:


An acronym is an abbreviation made from the initial (first) letters of a group of words. We say the acronym as a word, not as separate letters, for example:

acronym full form
Aids acquired immune deficiency syndrome
NASA National Aeronautics and Space Administration
UNESCO United Nations Educational, Scientific, and Cultural Organization
radar radio detection and ranging
scuba self-contained underwater breathing apparatus

Listen to how the acronyms are pronounced, as actual words:

One important difference between acronyms and initialisms is that all acronyms can be spoken like a word, initialisms usually cannot or are not. Notice that acronyms invariably contain vowels, initialisms rarely do.
Note that the above is a basic guide only. There are several complications and exceptions. For example, some abbreviations can be acronyms OR initialisms, depending on how we say them (for example faq OR F.A.Q. for "frequently asked questions"); and some shortenings occur when the beginning of the word has been cut off, or the beginning AND the end (for example phone for "telephone" and flu for "influenza"). For more on this topic see Abbreviations in our Writing section.