If you're unfamiliar with the podcasting world, you're likely in the dark about a show called Serial.

While it might be new to you, Serial has managed to hook millions of listeners and become the most successful podcast of all time. What's it about? Why's it so popular? What's a podcast? If you're asking those questions, keep reading to learn all the answers and more.

Serial is a podcast show from WBEZ Chicago, a noncommercial and public radio station. New episodes are free and available every Thursday. You can subscribe through iTunes or other audio platforms. You can also listen every week via Serial's website.

Serial, which is hosted by reporter Sarah Koenig and will soon air its final episode, was spun from This American Life, a weekly hour-long radio program hosted by Ira Glass and produced by WBEZ. According to its website, Serial has the follow description:

"Serial will follow one story - a true story - over the course of a whole season. We'll follow the plot and characters wherever they take us and we won’t know what happens at the end of the story until we get there, not long before you get there with us."

For those of you who want a more specific description... Serial is about an 18-year-old girl named Hae Min Lee. She was killed in 1999. Her ex-boyfriend, Adnan Syed, is in prison for her murder, but Serial addresses the possibility that he is actually innocent.

Like any series, it's important you listen to Serial in order and start at Episode 1. Each episode lasts from 30 minutes to an hour and features Koenig as she walks listeners through the once-shut case, interviews people, and uncovers new and startling facts.

Serial is widely considered the first major hit in podcasting history. According to podcast advertising company Podtrac, the first nine episodes captivated about 2.2 million listeners each. The top ten podcasts after Serial only have an average of 620,000 listeners each episode.

Serial

And if you go past the top 200 podcast shows, downloads and streams drop off to just 5,000 each episode. In other words: podcasts are very niche, but Serial indicates that many Americans are becoming more interested in alternative mediums for programming consumption.

Since Serial has become a major hit, fans have created a scholarship fund to honor Hae Min Lee. A Serial discussion group on Reddit, which has over 28,000 members, launched a drive on 15 December to raise $25,000. The funds will create a scholarship named after Hae Min Lee.

But that's not all: a new campaign on Indiegogo - called CrowdSolve - was inspired by Serial. It wants to obtain legal files and data related to various cases and build a platform that will provide anyone with the necessary tools to browse through that information and be detectives.

Both the Reddit discussion group and CrowdSolve illustrate how Serial is not just a spinoff podcast but rather a cultural phenomenon.

Podcast revenue tends to come from fundraising and advertisements. Both This American Life and MailChimp adverts, for instance, have funded the first season of Serial. For the second season of Serial, Koenig asked listeners for donations.

Serial has already received enough donations to produce a second season: "We don’t know yet what the story will be or exactly when we’ll be airing Season Two, but we’ll be working on it as soon as this season ends," the team behind Serial announced.

You can still donate money to the second season of Serial, here.

In a nutshell: a podcast is like a radio show. It's a digital audio file you can stream from the internet or download to a computer or mobile device. A podcast is typically available as a series, new episodes of which can be automatically received by subscribers.

The team behind Serial explained (in the video below) how you can easily start listening to a podcast and included step-by-step instructions about how to subscribe to the Serial podcast.