Language, Culture, Religion and Trade
The Harappan culture, much like that of the the Mesopotamian cuneiform and the Egyptian hieroglyphics, had a form of written language used for communication throughout their society in the Indus River Valley civilization. Consisting of over 400 characters, the language of the Harappan culture was recorded on stone slabs used for trading pottery and weapons. However, unlike the Mesopotamian and Egyptian forms of written language, the Harappan's language has so far proven to be indecipherable.
The Harappan society lived in cities that had many modern day functions to them, such as air-conditioning and in-door plumbing. Of course, it wasn't the kind of air-conditioning or in-door plumbing that we use today; it was more like a natural kind of air-conditioning created by the ingenious design of the buildings which allowed airflow to enter and run throughout the city buildings, and the in-door plumbing was created using tunnels that ran at a slope underneath the city, disposing of the waste. In the remains of the city, historians found very few remnants of battle; weapons, strategies, history of conflicts... etc. The Harappan society could've been a very peaceful society during it's prime.
A lot of the modern Indian religious beliefs and practices originated from the Indus River Valley civilization. Artifacts found in what was left over from the Harappan society, and drawing on walls of animals and characters that are assumed to be gods. Historians believe that the Harappan's worshiped a mother goddess. They also believe that the Harappans cultural religious was a theocracy, though there has been no sight or discovery of a temple in which the people or their priests could worship. They do, however, believe that the priests would pray for protection from the yearly floods, but also pray that these floods would bring fertile land.
The Indus River was a major trade route for many ancient civilizations at the time. The indus River connected many of the major cities and ancient civilizations together, meeting at the Indus River Valley civilization, and then also created a quick route to the ocean, premising long distance trade opportunities, even with cultures as far away as Mesopotamia and Sumer. The Harappan people traded with many different civilizations, both near and far; they traded with Mesopotamia, Summer, Afghanistan, Persia and the Deccan Plateau.