This video introduces the Amazon Kinesis Client Library (KCL), a Java library that simplifies consuming and processing data from Kinesis data streams. It covers key concepts like workers, leases, and record processors, explaining how KCL handles complex distributed computing tasks. The video also demonstrates how to develop custom consumer applications using KCL, including code samples for both shared and dedicated throughput consumers. Learn how KCL manages stream changes, load balancing, and fault tolerance, making it easier to build scalable stream processing applications.