Arrays are the most basic collection that C# offers. Think of them as containers for a group of values, called elements in programming terminology, each of which can be accessed or modified individually:
- Arrays can store any type of value; all the elements need to be of the same type.
- The length, or the number of elements, an array can have is set when it's created, and this can't be modified afterward.
- If no initial values are assigned when it's created, each element will be given a default value. Arrays storing number types default to zero, while any other type gets set to null or nothing.
Arrays are the least flexible collection type in C#. This is mainly because elements can't be added or removed after they have been created. However, they are particularly useful when storing information that isn't likely to change. That lack of flexibility makes them faster compared to other collection types.