Mission Statement is basically a very brief statement that outlines the purpose of a company or a department. The basic aim behind a mission statement is to keep all the stakeholders aware of the purpose of an organization's existence.
The mission statement of a department or a company largely depends on which sector it is working in. For a profit sector it would be different from a non- profit sector.
Here is a sample Mission statement that you can take help from:
" Our mission is to provide marketing support to our company in order to promote and communicate the value added by our company to the society, in front of the public."