The Large-Scale Matrix Routing service fulfills a single purpose: it calculates routing matrices (of travel times and/or distances) for a large number of origins and destinations.
This service is for you if you need to calculate a routing matrix
For the more detailed description see Use Cases.
It is difficult to enumerate all the use cases for such routing matrices due to the generality of matrices as such and their applications. However, there are two prominent examples.
One example is finding the nearest destination for a single origin, such as a taxi driver, or delivery truck. In this case, a 1:N matrix is calculated, and the smallest entry corresponds to the nearest destination (nearest in time or distance).
Another example is a set of problems often referred to as the traveling salesperson problem or TSP for short. The required input for solvers of any instance of TSP is a routing matrix.