Meta data is information that is not visible to visitors of a website, but is instead used to help search engines index and categorize the site. This can include things like the website's title, description, keywords, and copyright information. While meta data is not necessarily required for a website to function, it can be very helpful in making sure that the site comes up in relevant search results. For this reason, many website owners take care to carefully select their meta data, in order to ensure that their site is easily found by potential visitors.