Throw and Catch Events

An event that is located in a sequence flow can "throw" an event that can be "caught" by a catch event.

Additionally, throw events are distinguished from catch events on a diagram by having their symbol colored in:

Catch intermediate events can be placed in flow, or on a task border. An in-flow catch event halts the flow until the event is triggered. A catch event attached to a task border usually cancels the task when the event is triggered.