Antisocial personality disorder is an umbrella term. It includes both sociopathy and psychopathy.
We can say it is a spectrum and psychopathy is most severe form of it.
Here's what I found on the internet:
Like other types of personality disorder, antisocial personality disorder is on a spectrum, which means it can range in severity from occasional bad behaviour to repeatedly breaking the law and committing serious crimes. Psychopaths are considered to have a severe form of antisocial personality disorder.