Can you explain what an intermediate operation is in the context of data processing?

An intermediate operation in data processing is a function that transforms a data stream but does not execute it immediately. In Java, for example, in the Stream API, intermediate operations (map, filter, sorted) create a new stream based on the previous one, but the computations only occur when a terminal operation (such as collect, forEach) is called.

Example:

List<String> names = Arrays.asList("Anna", "Bob", "Charlie");
List<String> filtered = names.stream()
    .filter(name -> name.startsWith("A")) // intermediate operation
    .map(String::toUpperCase)             // intermediate operation
    .collect(Collectors.toList());       // terminal operation

Here, filter and map are intermediate operations; they are not executed immediately but only when collect is called.