Can you explain the concept of data merging or calls through API into a single operation?

The concept of combining data or calls via API into a single operation is often implemented using the "aggregation" or "composition" pattern of requests. This allows the client to obtain all necessary data with a single request, reducing the number of network calls and increasing performance.

For example, in GraphQL, related data can be requested in one query instead of multiple REST calls.

In REST API, this can be implemented through endpoints that return aggregated data, for example:

GET /api/orders/123?include=customer,items

where the server returns the order along with customer and item information.

You can also use the "Batch API" pattern, where multiple requests are combined into one batch and sent simultaneously.

This improves UX and reduces network load.