An Algorithm is, well sort of a recipe.
An Algorithm is a series of operations to perform.
A Search Engine Algorithm is the series of operations that the search engines computers will follow when they calculate the ranking of websites. If You knew the algorithm of Google then You could build No 1 ranking websites all the time, as the algorithm would exactly show You what elements of a page are included in the calculation and which values would lead to optimal results.
Of course the search engine algorithms are kept secret, but a lot of factors that are used have been figured out by people doing SEO.
Google binary search feature most meaningful place to place is not safe because of its influence, but was sent to Google may be considered if the service of finding files. Currently, there are many documents, Google does not touch the wealth, also announced that Google will use multiple methods, which may include the times of high and low.
Search engine algorithm is the mechanics which search engines used to rank websites for searches. Search engine algorithms are always hidden from public, however, SEO guys are working on prediction and assumptions.