Precambrian time, period of time extending from about 4.6 billion years ago (the point at which Earth began to form) to the beginning of the Cambrian Period, 541 million years ago. Precambrian time encompasses the Archean and Proterozoic eons, which are formal geologic intervals that lasted from 4 billion to about 541 million years ago, and the Hadean Eon, which is an informal interval spanning from 4.6 billion to 4 billion years ago. The Precambrian represents more than 80 percent of the total geologic record.
It means exploiting the resources of the conquered country for the benefit of the conqueror. Imperialism means creating an empire, expanding into the neighbouring regions and expanding its dominance far. Colonialism is termed as building and maintaining colonies in one territory by people from another territory.
A law passed in 1966 under president Bill Clinton. Basically just a welfare reform.
