At it peak it was a spread over a truly gigantic geographical space. However the city architectures followed nearly same blue print. Which points to the existence of some kind of central planning.
It is known as a faceless civilisation because there wasn't an obviously kingly figure. No royal burials, no palaces, no extravagant houses etc., Of course there were rich and poor people but overall it seemed to be an egalitarian culture. Most houses are more or less uniformly well built.
The cities were divided into two sections; one part showing signs of more wealth than the other, suggesting ruling class of some sort. But again, it wasn't as if there was a king or as such.
There is no sign of war, destruction or violence. No weapons, no signs of burning/pillage etc.,
They traded with contemporary civilisations, predominantly with Mesopotamia.
Here's a good video but that's not easy find https://www.youtube.com/watch?v=_s5EDxuL0Vs