An abbreviation is a shortened form of a word or phrase, created by omitting certain letters or syllables. Common examples include Dr. for Doctor, Ave. for Avenue, and USA for United States of America. Abbreviations are often used to save time and space in writing, making communication more efficient. There are different types of abbreviations, including acronyms, which are formed from the initial letters of a series of words, like NASA for National Aeronautics and Space Administration. Abbreviations can be found in various fields, such as medicine, where terms like Rx represent prescriptions, and in technology, where Wi-Fi stands for wireless fidelity.