Dialogflow contexts are similar to natural language context. If a
person says to you “they are orange”, you need context in order to
understand what “they” is referring to. Similarly, for Dialogflow to
handle an end-user expression like that, it needs to be provided with
context in order to correctly match an intent. Using contexts, you
can control the flow of a conversation. You can configure contexts for
an intent by setting input and output contexts, which are identified
by string names. When an intent is matched, any configured output
contexts for that intent become active. While any contexts are active,
Dialogflow is more likely to match intents that are configured with
input contexts that correspond to the currently active contexts. For
more information about context, see the Contexts guide
<https://cloud.google.com/dialogflow/docs/contexts-overview>__.
Optional. The number of conversational query requests after
which the context expires. The default is 0. If set to
0, the context expires immediately. Contexts expire
automatically after 20 minutes if there are no matching
queries.