Hi Snagged,
No it’s just the mattress only so if you don’t have one already you would need a suitable metal or wooden bedframe and a foundation or a platform bed with a suitable support surface to support the mattress.
Dreamfoam sells a platform/bedframe combination here and a foundation here (that would need a metal or wooden bedframe) that would both be suitable and there is more about the different types of support systems that would be suitable for different types of mattresses and some sources for each of them in the foundation post here.
A headboard (or a footboard) isn’t necessary but if you do decide to buy one then it would be a personal preference choice based on your taste and preferences.
Phoenix