How does robots.txt differ from the ROBOTS META tag?
robots.txt is used to tell robots which parts of a site should not be visited, whereas the ROBOTS META tag tells a robot how to treat a specific page.
from The Web Robots Pages:
The ROBOTS META tag allows HTML authors to indicate to visiting robots if a document may be indexed, or used to harvest more links. No server administrator action is required.
Note that currently only a few robots implement this.
In this simple example:
a robot should neither index this document, nor analyse it for links.<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
Full details on how this tags works is provided:
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