an alphabetical list of words relating to a specific subject, text, or dialect.
A search engine results page (SERP) is the page displayed by a search engine when you ask it for some information.
An SERP usually contains:
• the search query (user search string) contained within a query box
• organic results (rich snippets, rich answers, google business listings, knowledge graph) which are customised depending upon the search query
• sponsored results.
Organic SERP are retrieved by the search engine's algorithm) where as sponsored are driven by advertisements. The results are normally ranked by relevance to the query. Each result displayed on the SERP normally includes a title, a link that points to the actual page on the Web and a short description showing where the keywords have matched content within the page for organic results. For sponsored results, the advertiser chooses what to display.
The search results displayed on the pages might differ due to difference in search intent. Try searching for Stephen Fry and then for London Heathrow to see how SERPs can vary.
Find more here: http://www.wordstream.com/serp