Social media versus social networks
Murthy (2013) provides a detailed introduction to Twitter and all its functions. He initially examines theoretical concepts and mechanisms and proceeds to relevant examples of good and poor practice on Twitter. He distinguishes between social media, social networks and micro-blogging and defines each of them through their own attributes.
According to Murthy, Twitter belongs to social media because it enables users to share content that is public by default. Murthy believes Facebook and LinkedIn are social networks where following users implies reciprocity and only “friends” or connections are able to access the content, which does not happen on Twitter. Therefore, according to Murthy, Twitter belongs to social media while Facebook and LinkedIn are social networks.
Citing Boyd and Ellison (2008, p.211) Murthy (2012) states that social networks are “web services which facilitate users maintaining a ‘public or semi-public profile within a bounded system’ and through which they can ‘articulate a list of other users with whom they share a connection’”.
Social media is actually an environment where “‘ordinary’ people in ordinary social networks (as opposed to professional journalists) can create user-generated ‘news’ (in a broadly defined sense)” (p.1061). The social dimension of social media makes it different from “traditional media” as the former “is designed to facilitate social interaction, the sharing of digital media, and collaboration” (p.1061).
In support to his statement Murthy (2012) explains:
For the sake of clarity, I define microblogging as an internet-based service in which (1) users have a public profile in which they broadcast short public messages or updates whether they are directed to specific user(s) or not, (2) messages become publicly aggregated together across users, and (3) users can decide whose messages they wish to receive, but not necessarily who can receive their messages; this is in distinction to most social networks where following each other is bi-directional (i.e. mutual) (p.1061).
In contrast with social network sites where “users often interact with people they know offline (Boyd, 2007; Ellison et al., 2007), users of social media often consume media produced by people they find of interest, leading to interactions with strangers and, albeit more rarely, celebrities” (Murthy, p.1061).
 Murthy, D. (2013), Twitter: Social Communication in the Twitter Age, Cambridge, Polity Press.
 Murthy, D. (2012), “Towards a Sociological Understanding of Social Media: Theorizing Twitter” in Sociology, 46(6), pp. 1059-1073, Sage