When is Voluntarily Causing Hurt and Causing Hurt by Doing a Rash Act the Same Thing?

Yaar, samajh nahi aaya! In IPC 319 and IPC 335, I got confused ki kya yeh dono hi ek hi shabd hai? Both deal with 'causing hurt' but IPC 319 is about voluntarily causing hurt while IPC 335 is about causing hurt by doing a rash act. What's the diff? Can someone please explain why both have separate sections? I mean, voluntary causing hurt implies rash act toh? Or is it the other way round? Is IPC 335 just a subset of 319 or vice versa? Please help before my exam. CLAT UG k liye toh yeh confusion khatarnaak hai!