Now that we’ve covered up Indexing in our last lesson, we will be tackling retrieval which is the second step of a search engine’s function.
Getting it out
Retrieval is basically when the search engine gets a query, looks over it’s index database and regurgitates whatever is relevant to the search terms (or keywords). It is a critical function of the search engine for us end-users because this is what we use search engines for.
Saving to Load
The only purpose of saving a document is to be able to load it some time in the future, right? We’ve covered up indexing wherein the search engine saves away webpages in it’s index database. And it’s purpose is so that it can be retrieved or loaded when a query is made by the end-user.
When you make a search query, Google (again, we’re using Google as an example) goes through all it’s data in it’s index database and looks for the keywords matching your search query. When it has found all the relevant ones, it will retrieve it out of it’s database and proceed to rank it before releasing it to you.
Retrieval is critical because some search engines such as Yahoo and Ask still read meta tags such as your meta description during its retrieval process – though it is not used for ranking nor does it affect ranking in any way. Still, it has some bearing on the search engine results page when it gives you the result.