Well for starters there wasn't just one East India Company, however the basic concept is a company commissioned by a government to set up trade in a foreign land. The best example was The British East India Company, it was commissioned by the English Crown to set up trade with various partners in mainly South Asia. The company had its own army to control and protect its goods. In 1757 the company gained administrative control over the British territories in India, which meant Britain still controlled the land and gained income from it, but the company took care of it and managed it. East India Companies were almost like small mobile countries, and in many respects they were.