What is the Difference between List, Set and Map in Salesforce?

The key differences between List, Set, and Map in Salesforce are:

1. List is an ordered collection of elements that can contain duplicates, Set is an unordered collection of unique elements, and Map is a collection of key-value pairs.
2. List is accessed by index position, Set does not support index position and is accessed by the value itself, and Map is accessed by the key.
3. List maintains order, Set does not maintain order, and Map does not guarantee order.
4. List is useful when you need to maintain order and access elements by their index position, Set is useful when you need to perform operations on unique elements, and Map is useful when you need to access elements by a specific key.