Any node that is capable of running the code in a cluster can be said to be a worker node. The driver program needs to listen for incoming connections and then accept the same from its executors. Additionally, the driver program must be network addressable from the worker nodes.
A worker node is basically a slave node. The master node assigns work that the worker node then performs. Worker nodes process data stored on the node and report the resources to the master node. The master node schedule tasks based on resource availability.
