the wikipedia explanation of postpunk is pretty accurate:
“Post-punk is a popular musical movement with its roots in the late 1970s, following on the heels of the initial punk rock explosion of the mid-1970s. The genre retains its roots in the punk movement but is more introverted, complex and experimental. Post-punk laid the groundwork for alternative rock by broadening the range of punk and underground music, incorporating elements of Krautrock (particularly the use of synthesizers and extensive repetition), Jamaican dub music (specifically in bass guitar), American funk, studio experimentation, and even punk’s traditional polar opposite, disco, into the genre. It found a firm place in the 1980s indie scene, and led to the development of genres such as gothic rock, industrial music and alternative rock.”
this time’s post punk bonus track is gang of four’s ‘anthrax’:
for more on post punk i recommend simon reynolds’ very thorough books on the topic: