The Flexible content field acts as a blank canvas to which you can add an unlimited number of layouts with full control over the order.
Build up your page with layouts
Similar to the repeater field, this field contains sub fields. However, instead of 1 set of sub fields, the flexible content field allows you to create an infinite set of sub field groups (called layouts). With these layouts predefined, you can then add them into your field when ever you want and where ever you want.