diff --git a/doc/api/cluster.md b/doc/api/cluster.md
index 609a334d97917c..34faac9a0be663 100644
--- a/doc/api/cluster.md
+++ b/doc/api/cluster.md
@@ -6,9 +6,11 @@
 
 <!-- source_link=lib/cluster.js -->
 
-A single instance of Node.js runs in a single thread. To take advantage of
-multi-core systems, the user will sometimes want to launch a cluster of Node.js
-processes to handle the load.
+Clusters of Node.js processes can be used to run multiple instances of Node.js
+that can distribute workloads among their application threads. When process
+isolation is not needed, the [`worker_threads`][] module can be used instead,
+which allows running multiple application threads within a single Node.js
+instance.
 
 The cluster module allows easy creation of child processes that all share
 server ports.
@@ -1122,3 +1124,4 @@ socket.on('data', (id) => {
 [`process` event: `'message'`]: process.md#event-message
 [`server.close()`]: net.md#event-close
 [`worker.exitedAfterDisconnect`]: #workerexitedafterdisconnect
+[`worker_threads`]: worker_threads.md