Social Network Sites: Definition, History,and Scholarshipdanah m. boydSchool of InformationUniversity of California-BerkeleyNicole B. EllisonDepartment of Telecommunication, Information Studies, and MediaMichigan State UniversitySocial network sites (SNSs) are increasingly attracting the attention of academic andindustry researchers intrigued by their affordances and reach. This special theme sectionof the Journal of Computer-Mediated Communication brings together scholarship onthese emergent phenomena. In this introductory article, we describe features of SNSsand propose a comprehensive definition. We then present one perspective on the historyof such sites, discussing key changes and developments. After briefly summarizing exist-ing scholarship concerning SNSs, we discuss the articles in this special section and con-clude with considerations for future research.doi:10.1111/j.1083-6101.2007.00393.xIntroductionSince their introduction, social network sites (SNSs) such as MySpace, Facebook,Cyworld, and Bebo have attracted millions of users, many of whom have integratedthese sites into their daily practices. As of this writing, there are hundreds of SNSs,with various technological affordances, supporting a wide range of interests andpractices. While their key technological features are fairly consistent, the culturesthat emerge around SNSs are varied. Most sites support the maintenance of pre-existing social networks, but others help strangers connect based on shared interests,political views, or activities. Some sites cater to diverse audiences, while others attractpeople based on common language or shared racial, sexual, religious, or nationality-based identities. Sites also vary in the extent to which they incorporate new infor-mation and communication tools, such as mobile connectivity, blogging, and photo/video-sharing.Journal of Computer-Mediated Communication210 Journal of Computer-Mediated Communication 13 (2008) 210–230 ª 2008 International Communication AssociationScholars from disparate fields have examined SNSs in order to understand thepractices, implications, culture, and meaning of the sites, as well as users’ engage-ment with them. This special theme section of the Journal of Computer-MediatedCommunication brings together a unique collection of articles that analyze a widespectrum of social network sites using various methodological techniques, theoret-ical traditions, and analytic approaches. By collecting these articles in this issue, ourgoal is to showcase some of the interdisciplinary scholarship around these sites.The purpose of this introduction is to provide a conceptual, historical, andscholarly context for the articles in this collection. We begin by defining what con-stitutes a social network site and then present one perspective on the historicaldevelopment of SNSs, drawing from personal interviews and public accounts of sitesand their changes over time. Following this, we review recent scholarship on SNSsand attempt to contextualize and highlight key works. We conclude with a descrip-tion of the articles included in this special section and suggestions for future research.Social Network Sites: A DefinitionWe define social network sites as web-based services that allow individuals to (1)construct a public or semi-public profile within a bounded system, (2) articulatea list of other users with whom they share a connection, and (3) view and traversetheir list of connections and those made by others within the system. The nature andnomenclature of these connections may vary from site to site.While we use the term ‘‘social network site’’ to describe this phenomenon, theterm ‘‘social networking sites’’ also appears in public discourse, and the two terms areoften used interchangeably. We chose not to employ the term ‘‘networking’’ for tworeasons: emphasis and scope. ‘‘Networking’’ emphasizes relationship initiation, oftenbetween strangers. While networking is possible on these sites, it is not the primarypractice on many of them, nor is it what differentiates them from other forms ofcomputer-mediated communication (CMC).What makes social network sites unique is not that they allow individuals to meetstrangers, but rather that they enable users to articulate and make visible their socialnetworks. This can result in connections between individuals that would not other-wise be made, but that is often not the goal, and these meetings are frequentlybetween ‘‘latent ties’’ (Haythornthwaite, 2005) who share some offline connection.On many of the large SNSs, participants are not necessarily ‘‘networking’’ or lookingto meet new people; instead, they are primarily communicating with people who arealready a part of their extended social network. To emphasize this articulated socialnetwork as a critical organizing feature of these sites, we label them ‘‘social networksites.’’While SNSs have implemented a wide variety of technical features, their back-bone consists of visible profiles that display an articulated list of Friends1who arealso users of the system. Profiles are unique pages where one can ‘‘type oneself intobeing’’ (Sunde´n, 2003, p. 3). After joining an SNS, an individual is asked to fill outJournal of Computer-Mediated Communication 13 (2008) 210–230 ª 2008 International Communication Association 211Figure 1 Timeline of the launch dates of many major SNSs and dates when community sitesre-launched with SNS features212 Journal of Computer-Mediated Communication 13 (2008) 210–230 ª 2008 International Communication Associationforms containing a series of questions. The profile is generated using the answers tothese questions, which typically include descriptors such as age, location, interests,and an ‘‘about me’’ section. Most sites also encourage users to upload a profile photo.Some sites allow users to enhance their profiles by adding multimedia content ormodifying their profile’s look and feel. Others, such as Facebook, allow users to addmodules (‘‘Applications’’) that enhance their profile.The visibility of a profile varies by site and according to user discretion. Bydefault, profiles on Friendster and Tribe.net are crawled by search engines, makingthem visible to anyone, regardless of whether or not the viewer has an account.Alternatively, LinkedIn controls what a viewer may see based on whether she orhe has a paid account. Sites like MySpace allow users to choose