Explain the main components and principles of Java Collections Framework.

Java Collections Framework (JCF) is a set of interfaces and classes for working with groups of objects.

Main components:

• Interfaces: Collection, List, Set, Queue, Map — define the behavior of collections.
• Implementations: ArrayList, LinkedList, HashSet, TreeSet, PriorityQueue, HashMap, TreeMap, etc.
• Utilities: the Collections class with methods for sorting, searching, synchronization.

Principles of operation:

• Collections allow storing and managing sets of objects of different types.
• Interfaces provide a unified API, which simplifies replacing implementations without changing code.
• Using generics allows working with type-safe collections.
• Some collections are ordered (e.g., List), others are unique (Set), and Map stores key-value pairs.

Example of usage:

List<String> list = new ArrayList<>();
list.add("apple");
list.add("banana");
for (String fruit : list) {
    System.out.println(fruit);
}