The key benefits of High Concurrency clusters are that they provide fine-grained sharing for maximum resource utilization and minimum query latencies.
Note that a Standard cluster is recommended for a single user. Standard clusters can run workloads developed in any language: Python, SQL, R, and Scala. High Concurrency clusters can run workloads developed in SQL, Python, and R. The performance and security of High Concurrency clusters is provided by running user code in separate processes, which is not possible in Scala. HC clusters should be used when running SQL, Python, and R and compute sharing between users is required.
Read more here: https://docs.databricks.com/clusters/configure.html#cluster-mode
