Some popular keywords in searches, according to Google Trends, are "Facebook," "YouTube," "Google," "you" and "free." Then, there are also the keywords "Hotmail," "Yahoo," "fb" and "mp3."
Google Trends is an online feature of Google that allows users to view the most popular keywords used in searches on Google over any period of time dating back to 2004. Keywords can be compiled by country and/or language or by what category on Google they were searched under, such as News or Images. Terms can also be compared, while a "Hot Searches" feature displays keywords trending at the present moment.
Google's Autocomplete feature is also useful in determining popular keywords. While searching with Google, popular suggestions start appearing as soon as a user types a letter. The most popular searches appear first, although if signed into Google these results are somewhat personalized. For a more general idea of popular keywords, sign out of Google before using the Autocomplete feature.
Bing Trends analyzes billions of searches that went through Bing for the previous year and displays them in a report-like fashion. Categories, such as "top sports moments" or "most searched celebrities," can be clicked to see what the most popular search keywords were for them. Bing also offers its Bing Keyword Research service, which compiles the most used keywords in searches, similar to how Google Trends functions. This requires a Microsoft account but results can be categorized by language or country going back up to six months.