When we discuss acronyms, we really need to clarify the difference between acronyms and initialisms,  acronyms are abbreviations formed from letters of other words, usually the letter of each first word.  The abbreviation must be pronounceable as a word.

Initialisms are also made up of letters of some name or term, and also usually with the first letter of each of the words contained in the name or term. But, with initialisms, the resulting set of letters is not pronounced as a word:

From www.wordhippo.com come these definitions:
ac·ro·nym
noun
an abbreviation formed from the initial letters of other words and pronounced as a word e.g. ASCII, NASA

in·i·tial·ism
noun
an abbreviation consisting of initial letters pronounced separately (e.g., CPU ). ab·bre·vi·a·tion
noun
a shortened form of a word or phrase.

“TODAY-   Turn On Dreams Abandoned Yesterday”   ― Kamil Ali

You should know the difference between an acronym and an initialism.

Both acronyms and initialisms are abbreviations, but there is a difference between the two, although recently some dictionaries have defined acronyms that actually cover the meaning of an initialism.  This may take hold as the general understanding of the meaning, but it is useful to know how grammarians understand the difference:

Acronyms are abbreviations formed from letters of other words, usually the letter of each first word.  The abbreviation must be pronounceable as a word.  Examples of this would be things like NASA (National Aeronautics and Space Administration), and OPEC (Organization of Petroleum Exporting Countries).

Initialisms are also made up of letters of some name or term, and also usually with the first letter of each of the words contained in the name or term. But, with initialisms, the resulting set of letters is not pronounced as a word and you spelt out each individual letter, such as CIA  for Central Intelligence Agency.

(An abbreviation is something different again. It is a shortened version of a word, such as Mr. as in Mister,  Ark. as in Arkansas, etc.)

Note that you do not have to use periods in either acronyms or initialisms.  Some people choose to, but this is a matter of style rather than a rule.

examples of acronyms and initialisms

acronyms

NASDAQ – National Association of Securities Dealers Automated Quotations
SOS – Save Our Ship
OPEC – Organization of Petroleum Exporting Countries
VIP – Very Important Person

initialisms

UN – United Nations
CIA – Central Intelligence Agency

contemporary examples

Acronym – wifi – wireless fidelity. LOL – Laugh Out Loud.
Initialism – CD – compact disc

Acronyms, initialisms and abbreviations are used regularly everywhere, in written and spoken English and is especially prevalent today in internet slang  or ‘netlingo.’  Here is a website http://www.netlingo.com/ with a comprehensive and continually updated list of acronyms, initialisms and abbreviations.

Acronyms are abbreviated words that form the initial letters of other words, and they are pronounced as a word; initialisms are abbreviations consisting of initial letters pronounced separately.