Does using Stream modify the original collection during operation?

Using Stream in Java does not modify the original collection during execution of operations. Streams provide a functional way to process data, and they do not modify the original collections.

All operations on a Stream are either intermediate, which return a new Stream, or terminal, which return a result but do not change the original data.

For example:

List<String> list = new ArrayList<>(Arrays.asList("a", "b", "c"));
Stream<String> stream = list.stream().filter(s -> s.startsWith("a"));
// The original list remains unchanged

Thus, Stream ensures the immutability of the original collections during processing.