Isn't a sociopath very similar, but is scared of dying?
It's likely more complicated than that, but that was my simplistic take from Googling it a few years back.
I also heard somewhere that our personalities have a certain percentage of every trait. Which makes sense, due to when you do online autism, (or whatever) tests that pop out a percentage at the end.
There are a lot of similarities but, depending on who you ask, there are some differences. Broadly, sociopaths aren't as good at self regulation - they are more reactive and impulsive. As such, they tend to be easier to spot and end up in prison more often. It's complicated though. Both words fall under ASPD now.