The Holocene is the geological period we are currently in. It began 11,550 years ago, about 9,600 BC. The Holocene begins roughly when the last non-human member of the genus Homo, Homo floresiensis, died out. It was also the end of the Younger Dryas cold spell and the Wisconsin glaciation, during which huge areas of Canada, northern Europe, and Asia were covered in ice sheets 2-3 km thick. This most recent glaciation, which lasted 52,000 years, created many of the Northern hemisphere's most beautiful landscapes. The Holocene was preceded by the Pleistocene, during which most of our species' evolution took place. The Pleistocene began 1.8 million years ago.
All of human civilization has occurred during the Holocene. Some historians put the first evidence of civilization in 9500 BC, the age of the oldest known granary, only 100 years after the beginning of the Holocene. The oldest Japanese potteries date to 10,000 BC. The oldest known human settlement, Jericho, was founded around 9000 BC. Approximately 3500 BC was the beginning of the Bronze Age, when humanity finally went beyond using stone to fashion tools. The dawn of agriculture is generally placed around 8000 BC.
Around the beginning of the Holocene, the worldwide human population was somewhere around 5 million. Today the human population is approaching 7 billion. Clearly, the most obvious hallmark of the Holocene period thus far is humanity's meteoric rise in both population and technological advancement. We have gone from using stone tools, to bronze, to iron, and then to a variety of synthetics include plastic and advanced alloys.
In the early Holocene, glaciers melted on a massive scale, opening up many millions of square miles for human colonization and just generally making life for Homo sapiens easier. The Holocene has seen the emergence of new species like the domestic dog and cat, and the success of species that thrive on human expansion, such as the house mouse and raccoon. The Holocene began with the Neolithic revolution, in which human culture exploded and cheap methods of food production, such as the use of beasts of burden for agriculture, became popular.