Google and other big search engines ignore common words such as ‘the’, ‘of’, ‘where’, as wel as certain single digits and single letters. These words are called “filter words”. They are ignored because they tend to slow down a search without improving the results.
Of course, every search engine has its own list of filter words. We’ve found out that the following words seem to be ignored by most search engines:
a, about, an, and, are, as, at, be, by, from how, i, in, is, it, of, on, or, that, the, this, to was, we, what, when, where, which, with.