A memo is a short piece of text, whose main function is to record important information. The term memo is short for the slightly longer term memorandum, a word of Latin origin which in its initial full form - memorandum est - means 'it is to be remembered', according to the Oxford English Dictionary. A memo is used as an official note inside an organisation or a company.
In terms of the language use of the term, the short version memo works in most situations except for very formal contexts, where the longer term memorandum is preferred. There are different variants of the plural form, with memos for the short term and memoranda or memorandums for the full term being the predominant ones. (The Swedish corresponding term for memo is PM, which is short for promemoria, from Latin pro memoria 'for memory'.)
Traditionally, a memo consists of an initial part called the header, indicating who the sender and the intended receiver is, the date, and a subject line. Then, there is a second part called the message, where the actual information of the memo is provided. This part can vary greatly in style, length and detail, depending on the purpose of the memo. Finally, there may be some sort of closing, but in some cases this is excluded, as is salutations.
In terms of formality, memos are not as formal as letters. Memos vary in format and the way they are sent. Some organisations use standard, printed forms. It should also be noted that it is very common nowadays for memos to be sent in the form of ordinary e-mails. In those cases, the initial section with sender, receiver, date and subject line is integral to the e-mail format.
Click on the links below to see examples of simple memos.