Spark Streaming wasn't the first streaming architecture. Over time, multiple technologies have been developed in order to address various real-time processing needs. One of the first popular stream processor technologies was Twitter Storm, and it was used in many businesses. Spark includes the streaming library, which has grown to become the most widely used technology today. This is mainly because Spark Streaming holds some significant advantages over all of the other technologies, the most important being its integration of Spark Streaming APIs within its core API. Not only that, but Spark Streaming is also integrated with Spark ML and Spark SQL, along with GraphX. Because of all of these integrations, Spark is a powerful and versatile streaming technology.
Note that https://spark.apache.org/docs/2.1.0/streaming-programming-guide.html has more information...
