Delta Lake is basically a compute layer that would sit on top of your existing On Prem HDFS cluster, your favourite Cloud storage or even run it locally on your laptop(Best part)! Data is stored on the above-mentioned storage as versioned Parquet files. Any data that is read using Spark can be used to read and write with Delta Lake. Delta lakes provides an unified platform to support both Batch Processing and Stream processing workloads on a single platform.
Read on to understand just how useful this is.