Arrays and collections allow you to manage groups of objects. You can access a particular object by index in both arrays and collections, and you can use For Each…Next (foreach) syntax to iterate through the members of arrays and most collections. Arrays are fixed in length, and members must be initialized before use. Members of collections must be declared and initialized outside of the collection, and then added to the collection. Collections provided in the System.Collections namespace can grow or shrink dynamically, and items can be added or removed at run time.