We 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) articulate a list of other users with whom they share a connection, and (3) view and traverse their list of connections and those made by others within the system. The nature and nomenclature of these connections may vary from site to site. While we use the term 'social network site' to describe this phenomenon, the term 'social networking sites' also appears in public discourse, and the two terms are often used interchangeably. We chose not to employ the term 'networking' for two reasons: emphasis and scope. 'Networking' emphasizes relationship initiation, often between strangers. While networking is possible on these sites, it is not the primary practice on many of them, nor is it what differentiates them from other forms of computer-mediated communication (CMC).What makes social network sites unique is not that they allow individuals to meet strangers, but rather that they enable users to articulate and make visible their social networks. On many of the large SNSs, participants are not necessarily 'networking' or looking to meet new people; instead, they are primarily communicating with people who are already a part of their extended social network. To emphasize this articulated social network as a critical organizing feature of these sites, we label them 'social network sites.' While SNSs have implemented a wide variety of technical features, their backbone consists of visible profiles that display an articulated list of Friends who are also users of the system. Profiles are unique pages where one can 'type oneself into being'. After joining an SNS, an individual is asked to fill out forms containing a series of questions. The profile is generated using the answers to these 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 or modifying their profile's look and feel. After joining a social network site, users are prompted to identify others in the system with whom they have a relationship. The label for these relationships differs depending on the sitepopular terms include 'Friends,' 'Contacts,' and 'Fans.' SNSs require bi-directional confirmation for Friendship. The one-directional ties are sometimes labeled as 'Fans' or 'Followers,' but many sites call these Friends as well. The public display of connections is a crucial component of SNSs. The Friends list contains links to each Friend's profile, enabling viewers to traverse the network graph by clicking through the Friends lists. The list of Friends is visible to anyone who is permitted to view the profile, although there are exceptions. SNSs also provide a mechanism for users to leave messages on their Friends' profiles. This feature typically involves leaving 'comments,' although sites employ various labels for this feature. In addition, SNSs have a private messaging feature similar to webmail. Beyond profiles, friends, comments, and private messaging, SNSs vary greatly in their features and user base. Some have photo-sharing or video-sharing capabilities; others have built-in blogging and instant messaging technology. SNSs target people from specific geographical regions or linguistic groups, although this does not always determine the site's constituency. These sites are designed with specific ethnic, religious, political, or other identity-driven categories in mind.We 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) articulate a list of other users with whom they share a connection, and (3) view and traverse their list of connections and those made by others within the system. The nature and nomenclature of these connections may vary from site to site. While we use the term 'social network site' to describe this phenomenon, the term 'social networking sites' also appears in public discourse, and the two terms are often used interchangeably. We chose not to employ the term 'networking' for two reasons: emphasis and scope. 'Networking' emphasizes relationship initiation, often between strangers. While networking is possible on these sites, it is not the primary practice on many of them, nor is it what differentiates them from other forms of computer-mediated communication (CMC).What makes social network sites unique is not that they allow individuals to meet strangers, but rather that they enable users to articulate and make visible their social networks. On many of the large SNSs, participants are not necessarily 'networking' or looking to meet new people; instead, they are primarily communicating with people who are already a part of their extended social network. To emphasize this articulated social network as a critical organizing feature of these sites, we label them 'social network sites.' While SNSs have implemented a wide variety of technical features, their backbone consists of visible profiles that display an articulated list of Friends who are also users of the system. Profiles are unique pages where one can 'type oneself into being'. After joining an SNS, an individual is asked to fill out forms containing a series of questions. The profile is generated using the answers to these 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 or modifying their profile's look and feel. After joining a social network site, users are prompted to identify others in the system with whom they have a relationship. The label for these relationships differs depending on the sitepopular terms include 'Friends,' 'Contacts,' and 'Fans.' SNSs require bi-directional confirmation for Friendship. The one-directional ties are sometimes labeled as 'Fans' or 'Followers,' but many sites call these Friends as well. The public display of connections is a crucial component of SNSs. The Friends list contains links to each Friend's profile, enabling viewers to traverse the network graph by clicking through the Friends lists. The list of Friends is visible to anyone who is permitted to view the profile, although there are exceptions. SNSs also provide a mechanism for users to leave messages on their Friends' profiles. This feature typically involves leaving 'comments,' although sites employ various labels for this feature. In addition, SNSs have a private messaging feature similar to webmail. Beyond profiles, friends, comments, and private messaging, SNSs vary greatly in their features and user base. Some have photo-sharing or video-sharing capabilities; others have built-in blogging and instant messaging technology. SNSs target people from specific geographical regions or linguistic groups, although this does not always determine the site's constituency. These sites are designed with specific ethnic, religious, political, or other identity-driven categories in mind.
