Memo is stand for Memorandum and it is usually use for written some useful information for the business purpose.
Memo is known for its high versatile communication and it is usually used for the business purpose.
The memo is written for informing the readers about some new information, policies and about prices change in the business organization. The memo is basically divided into the two main parts that are:
The top subject information about the message
The main content of the message
Therefore, Ann should use a memo for informing about the hiring policies among more than hundred employees.