Definition of online

A state that marks a component in a failover cluster or server cluster as available. When a node is online, it is an active member of the cluster and can own and run clustered services and applications, honor cluster database updates, contribute votes to the quorum algorithm, and maintain heartbeats. Clustered services and applications, and the resources within them, also have an online state.

An item on the user’s My Status menu. This is a status the user can select while signed in, to make it appear to other users that he is currently online.

The status that appears when a user signs in. This status shows this user is available to call and IM on Skype.

Connected to the internet, or of the internet.