In C# an array is a fixed-size collection of elements of the same type. It is a data structure that allows you to store multiple values of the same type in a single variable. To declare an array in C# you need to specify the type of the elements it will hold followed by square brackets [] and the name of the array. For example to declare an array of integers you would write: int[] numbers; To initialize the array and allocate memory for its elements you can use the `new` keyword. For example: int[] numbers = new int[5]; This creates an array called `numbers` with a size of 5 meaning it can hold 5 integers. The elements of the array are automatically initialized to their default values (0 in the case of integers). You can also initialize an array with specific values at the time of declaration. For example: int[] numbers = { 1 2 3 4 5 }; This creates an array called `numbers` with the values 1 2 3 4 and 5. To access the elements of an array you can use square brackets [] with the index of the element you want to access. Array indices start at 0 so the first element of an array is at index 0. For example: int firstNumber = numbers[0]; // Access the first element numbers[2] = 10; // Update the third element to 10 You can also use loops such as `for` or `foreach` to iterate over the elements of an array. For example: for (int i = 0; i Arrays in C# have a fixed size meaning you cannot change the number of elements once the array is created. If you need a collection that can grow or shrink dynamically you can use other data structures like `List ` or `ArrayList`.