Any Internet-page can include next meta-data.
Title – data of page caption (description or its part which is given by search system as a lnk on a site). The main aim is to provide user general meaning of information written on a page.
Description is page description. This data are not visible by user and it is indicated at time of site description sometimes. According to
html tutorials, if the tag «Description» is relevant to the enquiry, description includes key phrase or its part. Site description displayed by search system in time of output is called snippet. This convenient tool for the manipulation by the method of tries and sekections of the site description in the search system on the definite request, or on the group of them.
Keywords – key enquiries. Enough old Meta-tag including list of key phrases. It is not taken into consideration by search systems in time of site ranking. To fill it or not you should desire yourself.