Meta tags known as Indexer directives they tell search engine that this web page be crawled first. It affects individual result while searching in search engine.
@raveenasenJun 15.2013 — #Indexer directives means to give information to indexer. They are used to pass instructions or information to search engine indexer like Google boat or Yahoo boat that they have which pages have indexed and which pages have not indexed.
@HanasonsJun 17.2013 — #Yes, it is related to indexing content in search engines, for quality purposes, Google has to decide which content is good for the society and which is not then the indexing process starts based on this.