A single piece of data in Splunk software, similar to a record in a log file or other data input. When data is indexed, it is divided into individual events. Each event is given a timestamp, host, source, and source type. Often, a single event corresponds to a single line in your inputs, but some inputs (for example, XML logs) have multiline events, and some inputs have multiple events on a single line. When you run a successful search, you get back events.
Similar events can be categorized together with event types.
For more information
In Getting Data In:
In the Knowledge Manager Manual: