What is the difference between "parce que" and "car"?

The difference between "parce que" and "car" is that the first is a subordinating conjunction and the second is a coordinating conjunction. "Parce que" can be used at the start of a sentence. It also introduces the direct cause of something. However, "car" can only be used after a comma; this is because it usually introduces something of a justification for what we have just said.To make things clearer, we can take two similar sentences.Marie est malade, car je ne l’ai pas vue aujourd'hui.Here we are justifying the sentence we have stated before 'car', or why we think Marie is ill (because we haven't seen her today).
Marie est malade, parce qu'elle a trop mangé.Here we are giving a direct cause as to why Marie is ill (because she has eaten too much). This isn't the justification behind what we think, but the reason behind her being ill.