People's mental models of the Internet tend to focus on the functional affordances of Internet-enabled devices. Given that today's adolescents and young adults (Generation Z) have grown up surrounded by the Internet, we examined the extent to which the Internet's ubiquity was salient in their mental models of it. Middleschool students (Study 1, N = 78, Mage = 13 years, Range 11-15) drew pictures and explained what the Internet looked like. Responses were coded for indicators of four facets of the Internet: technical components, functions, attributes, and feelings. The adolescents mostly described components as user hardware (i.e., Internet-enabled devices) and functions as information access or storage, socializing via social media, and communicating with others. About half described the Internet as "everywhere," suggesting awareness of the Internet's ubiquity, though few mentioned Internetenabled household objects. Students rarely described it as "connective" (i.e., a network) or mentioned negative feelings about the Internet (i.e., online antisocial behavior). In Study 2, college students' (N = 109, Mage = 19 years, Range 18-22) mental models mostly aligned with the adolescents, emphasizing Internet-based functions and devices. However, the young adults more often cited negative feelings, including Internet addiction. Across studies, mental models mostly did not differ by age, gender, self-reported grades, or social media use. Students' awareness of the Internet's ubiquity may offer a starting point for fostering understanding of how users' data are collected and used and associated privacy and security risks.