An acronym is often considered to be a type of abbreviation. Generally, if an abbreviation is pronounced as a word rather than as the letters individually, it is considered an acronym. Often the distinction isn't always made between acronyms and abbreviations, especially when the abbreviation is more widely known than what it stands for, such as "PVC" (polyvinyl chloride) and "ATM" (automated teller machine).
Acronyms often are capitalized, as in the Spanish CURT (for centro urbano de rehabilitación de toxicómanos, or a drug rehab center). Occasionally, acronyms form a word whose original meaning is nearly forgotten, such as "laser" (láser in Spanish), which comes from "l(ight) a(mplification by) s(timulated) e(mission of) r(adiation)."