Search Engine Optimization (SEO) is a tool that attempts to improve rankings and visibility for non-paid search engine results. SEO is something new to me, and at first the concept seemed difficult to understand, but luckily it can be broken down to be pretty simple by websites like WordPress.com. WordPress uses a plugin called Yoast SEO to help you make your site search-engine friendly based on the following material

Content

YOAST will analyze your content and “rate” it as red, orange or green, based on a variety of pieces. (See content analysis below.)

Snippet

You can edit what comes up when someone Googles your article or website by changing the meta description. Typically, the meta description is a preview of the first few words of the article. Ideally, it will contain keywords or phrases that are relevant to the article.

Keyword
Choosing a keyword can be difficult, because you are essentially trying to take an entire article or page and sum it up in one singular word (or a few keywords.) If a word is stated in the title and the meta description, it is likely a good option to use as a keyword

Content Analysis

Your content will be “graded” on a variety of pieces including the use of a photo in your piece, the use of your keyword throughout your article, especially in your URL, title, meta description and subheads, the presence of outbound links and word count, among other things.

Categories and Tags

WordPress also allows you to categorize and tag your content to make it easy to find. Categories should be broad topics like business, marketing, productivity or professional development. Tags should be more specific based on articles like Proforma, organization or internship.

While this information is based on what I know about WordPress SEO criteria, other non-paid pieces are based on the same or similar criteria.