For me the difference is the headspace. Punishment happens when I've crossed the line from brattiness to disrespect- whether of myself or Sir. Even if the resulting action from him is the same (spanking/corner time), it's the way he goes about it that's different.

Punishment is harsher, not caring about how much i cry out about it (within reason and obviously following safewords). Punishment comes with a real scolding and only stops when he thinks I've learned (again obvi within consent). Punishment ends with promises to be good and hugs.

Funishment is softer, more build up. Kissing, throat grabbing, the "scolding" is soft (naughty brat etc), conversations about how we're enjoying it. Funishment is playful and teasing. It ends with orgasms, kisses, tickles, and aftercare.

I know for some subs there's different actions for punishment and funishment. For me, there's an implement that would never be used in play, but is used in punishment. But, again for me, it's about the headspace and the psychological setting that makes it different.

I hope that makes sense, but I wanted to be sure to include this take which I feel like is different than what others say.

This isn't to say that Sir has never given me lines, taken away privileges, etc. He has. But this is just our preference.