for your publisher to include in the metadata of the page, which is part of the HTML code.
Key phrases and keywords are words, or combinations of words, that people would use to search for information on the topic about which you are writing. For example, key phrases for an article on moving could be "packing and moving" or "loading a moving truck," while keywords could be "moving," "relocation," or "relocating."
Key phrases and keywords are registered by so-called "spiders," which are scripts that search engines send out to every page on the Internet. These spiders "crawl" across web pages and websites and analyze them for content and quality of content. One of the ways they do this is to register the keywords and key phrases to determine the subject of a page; but they also detect how often each key word or phrase is used, whether a page is grammatically correct, and what types of inbound and outbound hyperlinks there are. Hyperlinks are links to other pages that are somehow relevant to your topic.