Metadata
Metadata is basically just the stuff on your website that tells the search engines what your site is about. This information is hidden so that people who visit your site can't see it. There used to be a time when metadata was a critical factor in search engine rankings but that is really no longer the case, Google doesn't even consider it anymore. That being said it is still a good idea to fill out this information correctly because it can still help you to get visitors. This of course assumes that you understand how to use metadata correctly and fill it out properly.
In the early days of the internet search engines used metadata as a way to determine what a website was about, mainly because they had no other way to do it. Since then the search engines have gotten much more sophisticated and they really don't need the metadata to tell what a site is about, which is a good thing because webmasters where using metadata as a way to game the system. It didn't take webmasters long to figure out that if they stuffed as many keywords as they could into the meta description of their site they would be able to trick the search engines into ranking them for terms they really shouldn't have ranked for. Since this meant the search engines where returning results that weren't relevant they had to come up with a way of deciding what a site was about with out using metadata. Google no completely ignores metadata but some of the other search engines still use it as a small part of the rankings.
Just because the search engines don't use the metadata as a way to rank websites doesn't mean you should ignore it, there is still SEO value to using the metadata properly according to SEO-Tutorial.net. When search engines return results they don't just include the title of the website they also include a brief description. This description comes from the metadata. Most people use the description to decide what the site is about and whether or not it is worth visiting. It is very common for people to skip over a result and click on the one below it because it has a better description. This is why it is important to make sure that you have your metadata filled out properly.
When filling out your metadata you want to make sure that you use your keywords, ideally right at the beginning of the description. People usually skim the description looking for their keywords so you want to make sure they are there and easy to see. It is also important that you keep your description short, there is a limited amount of space for it on the results page, the search engines will simply cut it off at the point they run out of room. Nothing looks more unprofessional than having your description cut of in the middle so make sure you keep it short.