Explanation
The cluster manager receives input from the driver through the SparkContext.
Correct. In order for the driver to contact the cluster manager, the driver launches a SparkContext. The driver then asks the cluster manager for resources to launch executors.
In client mode, the cluster manager runs on the edge node.
No. In client mode, the cluster manager is independent of the edge node and runs in the cluster.
The cluster manager does not exist in standalone mode.
Wrong, the cluster manager exists even in standalone mode. Remember, standalone mode is an easy means to deploy Spark across a whole cluster, with some limitations. For example, in standalone mode, no other frameworks can run in parallel with Spark. The cluster manager is part of Spark in standalone deployments however and helps launch and maintain resources across the cluster.
The cluster manager transforms jobs into DAGs.
No, transforming jobs into DAGs is the task of the Spark driver.
Each cluster manager works on a single partition of data.
No. Cluster managers do not work on partitions directly. Their job is to coordinate cluster resources so that they can be requested by and allocated to Spark drivers.
More info: Introduction to Core Spark Concepts * BigData