Wikipedia:Notability explained

Editors of Wikipedia who are engaged in content creation work will, almost inevitably get one or more of their articles nominated for deletion. This banner is among the top of Wikipedians' worst nightmares:

Most of the time, their article or articles were nominated for deletion because of a notability issue.

Let's say that you just had one of your creations nominated for deletion because the topic/subject is not notable; however, you are absolutely clueless over what notability on Wikipedia is. This guide will explain to the layman what notability is.

The gist of it
Wikipedia is not a discriminate collection of information. Including insignificant or unimportant subjects will increase the workload of Wikipedia, while making Wikipedia a cesspool of autobiographies and other articles that only a few readers will want to read.

The general notability guideline
If a topic [or subject] has received coverage in  that are, it is  to be suitable for a stand-alone article or list.

Notability, in most cases, is established by being covered in reliable media or publications; enough to meet the general notability guideline (commonly abbreviated to GNG or WP:GNG). The article meets the general notability guideline, if the above sentence is true for the subject. However, what do the highlighted terms mean?

Significant coverage
Significant coverage is source coverage that describes the topic or subject or aspects directly related to the topic or subject in detail. For example, an article in a newspaper that covers, either fully or substantially, a person's career, life, or another directly-related aspect, is significant coverage.

Coverage without much information is not significant coverage. If a source merely lists the topic/subject in question, and does not describe the topic/subject, then that source is not counted as significant coverage.

Additionally, if a source covers the topic/subject in question, but the coverage is not of the topic/subject itself, nor any directly-related aspects, then that source is not counted as significant coverage. For example, a major firm's report on a certain company's earnings or stock is not counted as significant coverage, as it covers the company's earnings, not the company or any directly-related aspect of the company (e.g. the history of the company); unless the report has detail about the company or its history.

Reliable sources
A reliable source is a published source with reputation of fact-checking and accuracy. As a rule of thumb, most newspapers, books, journals (including magazines), and audio or video, published by a third-party publisher are considered reliable. Be careful of tabloid journalism (the most popular ones being, as tabloid publications usually skimp on fact-checking, enforce an extreme political bias, speculate, and/or gossip.

Self-published media, including most books on sketchy websites, personal websites, blogs (excluding newsblogs), social networking publications, and largely user-generated content (i.e. content generated by the users of a site), are not considered reliable sources.

Independent of the subject
Sources that are given to establish notability must not be written by the subject, in whole or substantially; or at the subject's request. For example, advertising, press releases, the subject's website, and autobiographies don't count, even if published in a reliable source.

Presumed
A topic/subject that is notable can most likely be included, except if the topic/subject does not belong in an encyclopedia. What Wikipedia is not can be consulted as a list of non-encyclopedic topics.