Acronyms are words formed from the initial letters of other words, the initial letters of a multi-word name, or by combining initial letters or parts of other words. For example, the acronym SALT stands for the words Strategic Arms Limitations Talks, the acronym PsyOp stands for Psychological Operations, and radar stands for radio detection and ranging. Acronyms are pronounced as they are spelled, that is, as a word. Thus SALT is pronounced salt, and PET (Positron Emission Tomography), as in PET scan, is pronounced pet.
Some acronyms in common use:
FIFO - First In First Out
Hi-Fi - High Fidelity
KISS - Keep It Simple Stupid
NAFTA - North American Free Trade Agreement
NAND - Not And
Navaid - Navigational Aid
PUFs - Public Use Files
SEAL - Sea, Air, Land
SIM - Subscriber Identification Module
SWAT - Special Weapons And Tactics
Initialisms are words created from typically the first letters of the words in a phrase. They differ from acronyms in that initialisms are pronounced as their component initials, for example, DOD stands for Department Of Defense, and is pronounced dee-oh-dee.
Some initialisms in common use:
A.D. - Anno Domini (In the Year of Our Lord)
AKA - Also Known As
CIA - Central Intelligence Agency
GM - General Motors
LOL - Laughing Out Loud
NFL - National Football League
OMG - Oh My God
RFP - Request For Proposal
RNC - Republican National Committee
TBD - To Be Determined
Acronyms and initialisms are abbreviations. In general, abbreviations are used to shorten words or phrases. For example, Blvd is used as an abbreviation for Boulevard, and F is used as an abbreviation for Fahrenheit. Acronyms and initialisms are used to abbreviate names and terms. The plurals of acronyms and initialisms are usually formed by adding ís. See Acronym Plurals.
The use of abbreviations dates back to as early as the Roman Republic, where the given name Tiberius was abbreviated as Ti., and Senatus Populus Que Romanus (the Senate and the People of Rome) was abbreviated by the initialism SPQR. The more widespread use of acronyms and initialisms was driven by the advent of complex terminology, advances in communications during the twentieth century, and the desire for more rapid and efficient exchange of information. The acronym sitcom, for example, used for the term situation comedy, allows for quicker speech and shorter written communications.
See Acronym Finder.