When searching for a term or certain phrase in the search engine, the results you are given are organic search results, processed by the search engines algorithm. The results will also be tested by various other parameters such as the quality of the website as far as structure, content and links in addition to scores for user-based ranking.
Besides organic search results, there can also be results generated by Pay per click (PPC) processes in which content is aimed at the searcher based on search parameters.
For example, if you are searching for a specific make of appliance, stores near you will pop up in your results and the store will be charged a small fee for providing that link to you. In most search engines the two types of results are separately organized.