When creating forms one can use the PHP [] array syntax to have multiple form fields populate an array when the input is parsed in PHP, like this:-
<input type="text" name="myArray[]">
<input type="text" name="myArray[]">
What would you call these kind of fields? Array input fields, maybe?
Aside: the PHP docs for this type of form input can be found here
It just like a normal input form. But value to send is multiple value, therefore it just set like array type