The HTML <a> tag defines a hyperlink. The hyperlink code looks like this…
<a href="http://www.website.com/page-name.html" target="_self" title="Tooltip Text">Link Text</a>
The URL - marked in red - can be a relative or an absolute file path. See THIS page for more info about file paths.
The target - marked in blue - defines how the linked page or is opened.
target="_self" is the default and the page or file opens in the same browser window. It is not necessary to specify this target as it is the browser default.
target="_blank" will open the page or file in a new browser window. NOTE: This should only be used when absolutely necessary as many visitors will find this irritating!
target="_top" is useful if you want a hyperlink which is contained in an iframe to open in the full browser window rather than in the confines of the iframe.
The title attribute - marked in purple - will show up in the browser default tooltip when the link is hovered for more than a few seconds. This tooltip looks rather ugly and, although the tooltip text is helpful to both humans and the search engine spiders, it can be omitted for the sake of appearance.
The link text - marked in green - is what the visitors see and click to follow the link.