Acronym refers to "what does it stand for"
An acronym as a word (as NATO, radar, or snafu) formed from the initial letter or letters of each of some specific terms. The title inside the tag gives the full abbreviation of the word. An acronym can be a abbreviation but not all abbreviation can be an acronym.
Some abbreviations can have unexpected pronunciations, such as being pronounced as a word rather than letter-by-letter. Contrary to what some sources say, acronyms do not have to be pronounceable words. For example CBI is spelled out when spoken, whereas ISRO is pronounced like single word.