Stop words
SEO / Search Marketing
Common words (ex: a, to, and, is ...) which add little relevancy to a search query, and are thus are removed from the search query prior to finding relevant search results.
It is both fine and natural to use stop words in your page content. The reason stop words are ignored when people search is that the words are so common that they offer little to no discrimination value.
Conjunctions, prepositions and articles and other words such as AND, TO and A that appear often in documents yet alone may contain little meaning.
Enterprise Search
Words which are very frequent and have little meaning. They are removed and not indexed. In advanced enterprise search platforms, customers can control the list of stop words by managing the stop word dictionary.