Abbreviation is a shortened form of a word or phrase, by any method. It may consist of a group of letters or words taken from the full version of the word or phrase. Abbreviations can be initials only, a mixture of initials and words, or words or letters representing words in another language. Some types of abbreviations are acronyms, initialisms, contractions, and crasis. Acronyms are abbreviations pronounced by spelling out each letter, such as FBI, USA, IBM, and BBC. Contractions are shortened forms of words or phrases that use apostrophes, such as cant, dont, and wont. Crasis is the contraction of two vowels into one, such as Im, were, and theyre.

Abbreviations are commonly used in texting or chatting, social media, and other informal settings. For example, "hbu" is an abbreviation for "How about you?". Other examples of text abbreviations include LOL (laughing out loud), BRB (be right back), IMO (in my opinion), and TBH (to be honest) .

In summary, an abbreviation is a shortened form of a word or phrase, and it can take many forms, including acronyms, initialisms, contractions, and crasis. Abbreviations are commonly used in informal settings such as texting, chatting, and social media.