Title and Meta tags are very essential and basic part of search engine optimization. Title should be meaningful and description should be informative. Title and Meta tags pass information of web page to crawler. By title and meta tags, crawler gets to know about web page. Title and meta description should be present on every page of website. These should be unique for every page. There should not be duplicity in meta tags and title tags.
Standard length of title is 66 characters. You can use up to 125 characters in title. Google shows only 56 to 63 characters in results. Your main keyword should be on first or second place in title tag. It helps to increase keyword prominence. Same keyword should not be repeated again and again. It is called keyword stuffing. Search engines crawlers dislike this approach.
Meta description is too an essential part as title of the web page. Generally there are three basic meta tags are used. These are meta description, meta robots and meta keywords.
Meta descriptions are used to pass description, which is shown in search results. Length of description can be up to 350 characters. But only 156 to 163 characters are only shown in search results. This is not necessary that search engines will show only descriptions you write. Search engines may take content even from your web page to show in search results. It is called snippet. If your written description is relevant with your keyword (being searched), then only your description will be shown otherwise relevant content will be shown as description or snippet.
Syntax of Meta Description
Many search engines do not read these meta tags, still many SEO gurus use it. Google does not support these tags but yahoo supports them. Maximum 10 keywords should be used in meta keyword tags.
Syntax of Meta Keyword
This is used to restrict robots or search engine crawlers to access web page. You can restrict to index web page and restrict to follow links from your web page by robots meta tags. Same can be done by robots.txt. Two values are passed in meta robots namely: