DDoS is a complex beast, and can come in many different forms and strengths - as can your applications that you are trying to defend. As such, there are different DoS components dotted all over the F5 system, in LTM, AFM, AdvWAF, Silverline to name just a few.
Can you give an indication of the kind of application(s) you are trying to protect and/or what kind of DDoS issues you are up against?
If you're more interested in the general capabilities of the F5 system and how it can help you defend against these kinds of attacks, you can also have a look here: https://clouddocs.f5.com/training/community/ddos/html/
This is a set of labs that give you an overview of how to setup a variety of different DoS protections in the box.