A memo, according to Dr. Judith Newman, is a short piece of communication that conveys a person's thoughts, reactions or opinions on an issue. The key principle behind memos is that they must be short, because their main objective is to facilitate timely communication in a busy environment. One example of a memo letter can be found on the English Club website, but other business writing websites will have slightly different examples.
There are several different ways to approach memo writing depending on whether the memo is to be persuasive or informative. In all cases, clearly stating the purpose of the communication in the subject line is important. Keep all memos simple. The standard length of a memo is restricted to one page, which means that its content should be concise and have a clear and coherent message. Memos usually consist of several sections. These may include a heading section, an opening paragraph, the main body section and a closing paragraph, but you should only use the sections you need to convey your message effectively.
According to an article at Write Express, memos are used for a variety of purposes such as conveying information about policy changes, promotions or other staff issues to internal audiences, or promoting specific offers on goods and services.