When used in reference to the World Wide Web, "hit" means a single request from a Web browser for a particular item from a Web server. For example, opening a Web page that contains four graphics would record five hits to the Web server: one for the HTML Web page and one for each of the four graphics. 

"Hits" are often used as a rough measure of the popularity of a Web page. As noted, however, a hit can represent anything from a request for a tiny document or graphic to a request for an entire Web page.