Can you explain the concept of Stream in the context of using the Stream API in programming?

Stream in the context of Stream API is a sequence of elements supporting sequential and parallel aggregate operations. Streams do not store data themselves but provide a functional approach to processing collections, allowing filtering, transforming, and reducing data.

Example of using Stream in Java:

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

System.out.println(filtered); // [ANNA]

Here, Stream makes it easy and readable to process collections.