More than anything else, Wikipedia is an encyclopedia. Because of this, subjects in Wikipedia have to be notable enough to be considered encyclopedic.
A topic is notable if it has been the subject of several published works from sources that are reliable and independent. All topics must meet a minimum level of notability in order for an article on that topic to be included in Wikipedia. This requirement makes sure that there is enough reliable material to write a verifiable, encyclopedic article about the topic.
In addition, the subject itself must also be encyclopedic. Things such as video-game guides, memorials, instruction manuals, directories, lists of links, advertising, self-promotion, and dictionary definitions are not encyclopedic. These things are examples of what Wikipedia is not.
Is the subject of your article notable?
My article is about a notable and encyclopedic subject
My article is about a subject that may not be notable