In a distributed computing system, data co-location involves storing related or correlated data together on the same node or set of nodes within the system. This technique is used to optimize data access patterns and reduce the need for data movement across nodes during computation. Data co-location is particularly beneficial for workloads that involve frequent interactions or computations on related pieces of data. By keeping related data together, the system can minimize the need for inter-node communication, leading to improved performance and reduced latency. While distributing data across nodes is a broader concept related to data partitioning and distribution, data co-location specifically emphasizes the practice of keeping related data in close proximity to each other within the distributed system.