what is a memo?
A memorandum (abbrev.: memo) was from the Latin verbal phrase memorandum est, the gerundive form of the verb memoro, "to mention, call to mind, recount, relate", which means "It must be remembered (that)...". It is therefore a note, document or other communication that helps the memory by recording events or observations on a topic, such as may be used in a business office. The plural form of the Latin noun memorandum so derived is properly memoranda, but if the word is deemed to have become a word of the English language, the plural memorandums, abbreviated to memos, may be used. (See also Agenda, Corrigenda, Addenda)
All memos are structured similarly. They have the following elements:
•An addressee: Flush left, in capital letters, near the top of the page
•The sender: Flush left, in caps, immediately below the addressee
•Date: Flush left, in caps, immediately below the sender’s name
•Subject: Flush left, in caps, immediately below the date