I'm a little confused about Ice ages, glacial periods, and interglacial periods. Are these terms used interchangeably?

The Earth is currently in a geological ice age and has been for 2.6 million years. 

The default state for most of the past 2.6 million years has been a much colder average temperature. I can't include pictures well lately but search Google Images for "Antarctic (Vostok) ice core data for the last 400,000 years". And you'll notice two things:

--The warm interglacials look like brief interruptions

--The most recent interruption looks different, longer-lasting. This is the Holocene and it started about 8,000 years ago.  

You might also notice that average temperature during the glacial periods is somewhere between 6-7 C below today. Outside of geology, many people refer to these glacial periods (especially the most recent one) as "ice ages". Whatever, names are boring, call it what you will. What I find most interesting from this chart is that just with -6 C, we had glaciers miles high stretching from the Arctic all the way to southern Indiana. Sea levels were hundreds of feat lower, you could walk from Australia to New Guinea. Point being, a 6C change makes a big difference, and we are on track for a +4 C change just by the end of the century (at which point, of course, time doesn't stop.) 

You might notice something else having started in the past 8,000 years, and that is human civilization. A major climate shift is something that human civilization (i.e. not hunter gatherer humans) has never had to encounter. Hunter gatherers didn't have coastal cities, or significant fractions of the planet converted to permanent agricultural plots (in places where rain or rain-fed streams could always be counted on), or 8 billion people, or geopolitical borders. They were small nomadic tribes that could simply follow the herds. A major climate shift today, and a much more rapid one too, will be much more difficult to adapt to, and it's impossible to make the case that anything other than keeping the climate stable is preferable. 

These days words are meaningless.  The only thing that counts is who you voted for.  Public education was dead by 1995.  Nothing but robotrons blah blah blah.  Can't remember them big words?  Make up your own.

Below is the Vostok ice core analysis that goes back some 450,000 years, showing ice ages and the warm interglacial periods all caused by solar cycles. Notice also that CO2 levels follow temperature thus debunking the anthropogenic global warming hoax.

Alarmist ignored new climate science has identified galactic cosmic ray flux moderated by the Sun's activity level as being a powerful climate forcing agent. along with more recent high energy proton forcing contained in the solar wind. These and other discoveries have shown that the climate of the Earth has still many new unknown elements to it and that the highly simplified alarmist perceptions and beliefs are totally incorrect.

Since you are confused about ice age cycles it now explains why you have no concept of climate change and cling to the alarmist pseudoscience propaganda campaign designed to lure in gullible people just like yourself. 

Since it is in FACT impossible to determine the age of something beyond 100,000 years, the "millions of years" lies are pure propaganda.

These same liars try and claim dinosaurs only existed millions of years ago yet they have found FLESH on dinosaur fossils and AGAIN it's IMPOSSIBLE for flesh to lash more than a few thousand years.

They use circular logic by creating some fake reference that they claim without proof is millions of years old then reference their fake reference to the rest of their fake timelines

Lol @sad. Thanks for commiserating, anyway!