How do the approaches to using collections like List and Array differ in C#?

In C#, arrays (Array) have a fixed size, which is set at creation and cannot be changed. They provide fast access to elements by index and are suitable when the size of data is known in advance.

Lists (List<T>) are dynamic collections that can change their size during runtime. They are implemented based on arrays but automatically expand when new elements are added.

Main differences:

• Size: array is fixed, list is dynamic.
• Flexibility: list is convenient for adding/removing elements.
• Performance: arrays are faster for access and occupy less memory, lists are slightly slower due to size management.

Example of using a list:

List<int> numbers = new List<int>();
numbers.Add(1);
numbers.Add(2);
int first = numbers[0];

If the collection size is known and does not change, it's better to use an array. If dynamic size is needed — use a list.