-Message is a short communication sent from one person to another when one person cannot speak to another person directly.
-Imagine you are a student and today you have after school class and you forgot to tell your mother. Write a message to inform your mother.
    An essay is a piece of writing outlining the writer's perspective or story.
     - You should write in the introduction what your essay is about and what points it will cover.
     - You can plan this by identifying main points and write a paragraph on each point.
     - This may be a summary or evaluation of contents.
Notice is formal documentation which includes the fact of observing or paying attention to something targeting at a particular person or a group of persons.
Imagine you are the president of Computer Science Society of your university.Write a notice to invite members of Science Society for annual meeting
A Poster is a large notice announcing or advertising something.
Nowadays,emails are among the most commonly used means of communication in the world.