What is polyamory? What to know about poly relationships.

Two people fall in love, get married and stay exclusive until the end of their lives – that's classic monogamy for you. But not everyone follows this trajectory.

Some people might find they feel more comfortable and more like themselves if they are in polyamorous relationships. Celebrities have helped spread awareness about polyamory, including Willow Smith. (The daughter of Jada Pinkett Smith and Will Smith – opened up about being polyamorous on "Red Table Talk" two years ago.)

"With polyamory, I think the main foundation is the freedom to be able to create a relationship style that works for you and not just stepping into monogamy because that's what everyone around you says is the right thing to do, " Willow Smith said. "I was like, how can I structure the way that I approach relationships with that in mind?"

Here's a peek at what this type of relationship actually looks like.

What does polyamorous mean?

Polyamory means "multiple loves" – a word coined in the late 20th century, with Greek and Latin roots.

"It usually describes a particular approach to (consensual non-monogamy) that prioritizes ongoing emotional and sexual connections with multiple partners," Sheila Addison, a family and marriage therapist, previously told USA TODAY. It's not to be confused with polygamy, aka "multiple wives" – something typically associated with religious or cultural practices, she said.

In the U.S. it dates back at least to the "Free Love" and transcendentalist movements in the 19th century, though it grew popular with the counterculture and sexual liberation movements of 1960s and early 1970s, Adrienne Davis, professor of law and founder & co-director of the Law & Culture Initiative at Washington University in St. Louis, also previously told USA TODAY.

"I believe one could say that it is in a third wave today, with many people practicing it, especially on the West Coast and Pacific Northwest," Davis said. According to a 2016 study that sampled U.S. Census data from single adults, 20% of participants reported engaging in consensual non-monogamy at some point in their lifetime.

What is a poly relationship? What is ethical non-monogamy?

There are many different terms associated with polyamory, including:

• Consensual or ethical non-monogamy. These terms are synonymous and ways to describe polyamorous relationships. Polyamory is a type of consensual non-monogamy, per Psychology Today.

• Solo polyamory. This is when "polyamorists have multiple relationships but do not become intertwined with the other people," Davis said.

• Kitchen-table polyamory. A family-like bond between partners is encouraged. The web of all these relationships is referred to as a "polycule."

Is polyamory a sexuality?

No. Anyone of any gender or sexual orientation partakes in polyamory. Some people are in for sex but others are for emotional intimacy or a combination of the two, Davis said.

Addison added: "Some people who are asexual and/or aromantic may identify as polyamorous as well, but their descriptions and boundaries around their relationships are going to be personal and self-defined in those cases."

More on (open) relationships

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This article originally appeared on USA TODAY: What is polyamorous? The truth about poly relationships