Short answers, pulled from the story.
The Last Glacial Period ended about 11,700 years ago. It had begun approximately 110,000 years ago and reached its coldest, most expansive point around 26,500 years before the present, a moment known as the Last Glacial Maximum.
An ice age is a long-term climate state in which glaciers exist on Earth; a glacial period is a colder interval within an ice age when temperatures drop further and glaciers advance. Interglacials are the warmer stretches between glacial periods, and the Holocene is the current interglacial.
At least eight glacial cycles have occurred in the last 740,000 years. Across the last 650,000 years, the average works out to roughly seven cycles of glacial advance and retreat.
Changes in atmospheric composition and associated shifts in radiative forcing were among the primary drivers of glacial and interglacial climates. Changes in ocean circulation, biological productivity, and seawater acid-base chemistry likely caused most of the recorded climate fluctuations within those broader swings.
The Penultimate Glacial Period is the glacial episode that immediately preceded the Last Glacial Period. It began about 194,000 years ago and ended approximately 135,000 years ago, when the climate warmed into the Eemian interglacial.
Work by Berger and Loutre suggests the current warm period may last another 50,000 years based on orbital mechanics alone. Greenhouse gases being emitted into Earth's atmosphere and oceans may delay the next glacial period by an additional 50,000 years beyond that.