Metatags can be found at the top of any webpage by right-clicking and selecting "view source" or something similar from the browser menu that you get. You have likely heard that the big-boy search engines (except for Bing) ignore the keyword metatags because so many websites lied. Instead, they search the webpages content for keywords using their secret rules. Folklore has it that to be detected as a keyword, the phrase must appear from 3 to 5 times in full grammatical context, i.e., a sentence with a subject and verb and preferably an object. Too many occurrences will be rejected, as that was one of the early ways that dishonest SEO (so-called Search Engine Optimization) purveyors tried to trick the engines. However, I still recommend that you complete this metatag as a reminder of what you need to assure occurs in the body content of each page.
However, title and description metatags are still heeded by the search engines. As the name implies, the title tag is what shows up at the top of the browser, if you provide it. Otherwise, it's usually just the browser branding. Likewise, the description metatag is what will show up in the search engine result to elaborate on your URL (webpage address) content, again, if you provide it. Otherwise, the engine will likely just take, say, the first 25 words or less of the page content to assist the searcher in choosing which link to click on next.
The important point is that keyword phrases are desired by search engines in these metatags (and also in text using the "heading" tag). Unlike in the body text of a page, these are expected to include short attractive phrases. Engines want to see phrases here. So, you need to make these tags very descriptive and compelling. This is the legitimate way to get your keyword phrases recognized by the search engines, and it works.
However, title and description metatags are still heeded by the search engines. As the name implies, the title tag is what shows up at the top of the browser, if you provide it. Otherwise, it's usually just the browser branding. Likewise, the description metatag is what will show up in the search engine result to elaborate on your URL (webpage address) content, again, if you provide it. Otherwise, the engine will likely just take, say, the first 25 words or less of the page content to assist the searcher in choosing which link to click on next.
The important point is that keyword phrases are desired by search engines in these metatags (and also in text using the "heading" tag). Unlike in the body text of a page, these are expected to include short attractive phrases. Engines want to see phrases here. So, you need to make these tags very descriptive and compelling. This is the legitimate way to get your keyword phrases recognized by the search engines, and it works.