When people refer to meta tags, they are talking about the meta description and
meta keyword tags. Some search engines may display the meta description as part
of the search results, but the meta keywords tags generally does not appear in
search results.

Is it Worth it to Create Meta Tags?
I believe creating page specific meta description tags is worthwhile. I generally do
not spend time creating meta keywords tags.
What do Meta Tags Look Like?

Meta Keywords Tag
If your site does not have meta keyword tags, I would probably not recommend
spending the time to add them. If you add meta keywords while you are creating
pages, I wouldn’t spend more than a minute on each page. I probably wouldn’t list
any more than a few of them per page.

The meta keywords tag is not supported by many major search engines. While it is
important to choose the correct keywords for your page, the meta keywords tag
itself is not used by many top SEO experts.

Mike Grehan interviewed Jon Glick (formerly of Yahoo! Search) and asked him
about the meta keyword tag. Jon stated that the meta keyword tag is used to
include a page among a subset of search results, but is not used in determining the
relevancy of that page for the given search term.

If a word does not exist on a page, and is not in any of its inbound linkage data,
then search engines such as Yahoo! may not know to include the page in search
results unless it exists in the keyword tag. I usually do not use the meta keywords
tag on my pages (as it is not usually very important), but it can help you out if there
are many different ways to say your product names and you are not creative
enough to cover the permutations in your page copy. Usually it is better to cover
the permutations in your page copy with sections like alternate part numbers, etc.

The meta keywords tag is typically used to highlight a couple of the main keyword phrases on which a page is focused.

The meta description tag should be a few sentences to a paragraph of text that uses various versions of your keywords and describes the purpose of a given page.

Meta tags are only one small element of current search engine ranking algorithms.

If you use the meta keywords tag, it should be unique for each page upon which
you place it. The keywords tag is a good place to put common misspellings,
synonyms, and alternate versions of a word.

Sample Uses of the Meta Keywords Tag
• If you optimized a page for the keyword phrase drop shipping, you may
want to include the word dropshipping in your keywords tag, although if
the term is that competitive, keyword tags are not likely to matter.
• Notice how in my above example meta keyword tag, I spelled the word
optimization with an “s”. I targeted the spelling with a “z” on my page
and am placing “s” versions in my keywords tag. The term is likely
going to be too competitive to compete for using just a meta tag, but
most phrases are not going to be as competitive as search engine
optimisation.
• Some items are model 15-M or 15M or Canon 15-M or Canon 15M.
• Prescription is often mistyped as perscription.
If a term is competitive, it is going to need to occur in your page copy and/or inbound link text for you to rank well for it.