Think you know the difference between criminal aliens and undocumented immigrants?

During the vice presidential debate on Oct. 4, 2016, Republican candidate Mike Pence referred to undocumented immigrants as "criminal aliens" at least three times.

When the topic turned to immigration, moderator Elaine Quijano asked Pence what he would tell undocumented immigrants who have not committed violent crimes and wish to stay in this country. That's when he uttered a two-word phrase that needs to quickly be removed from our shared vocabulary: "criminal aliens."

Look, we get it. It's hard! Despite years of activists working to disassociate the word "alien" (and "illegal") from immigrants, sometimes your eyes don't work properly or you're real tired or something, and law-breaking extraterrestrial beings do look a whole lot like human beings just looking for a better life for themselves.

But have no fear. We're here to help you tell them apart!

This is a criminal alien. He's from outer space.

He's from another planet, and he's running away from the cops. Technically, he also just kidnapped a bunch of kids on bikes.

This is an undocumented immigrant. She's doing homework.

She's a high school sophomore and, like many high school students, she's doing her homework. She came to America with her family in 2000. Her dad works in construction.

The majority of undocumented immigrants say their number one reason for coming to the U.S. is to find a better life, inspired by the promise of the American dream.

This is a criminal alien. He's under arrest.

His name is Zod and he's a former Kryptonian general. He's also definitely not from planet Earth. He was accused of treason and banished to the Phantom Zone. When he escaped, he tried to destroy Superman and take Earth down in the process. So, yeah, he's not very nice.

These guys are undocumented immigrants. They're also brothers. They helped with cleanup efforts after Hurricane Katrina.

These brothers traveled together from their hometown of Paso Amapa, Mexico, to New Orleans shortly after Hurricane Katrina struck. They, like many others, came to the area to help with much of the cleanup work in the wake of the storm.

These are criminal aliens. They're from Mars.

They tried to invade Earth in the 1996 movie "Mars Attacks!" and unlike undocumented immigrants, their heads explode when they hear the song "Indian Love Call."

This is a group of immigrants. They're eating dinner.

As of 2014, just over half of all undocumented immigrants in the U.S. are Mexican. Believe it or not, the estimated number of immigrants moving from Mexico to America has decreased since 2009, down from 6.4 million to 5.8 million in 2014.

This is a criminal alien. He's in a police lineup.

His name is Groot and he is an extraterrestrial being. He was arrested with the other "Guardians of the Galaxy" after he and his friend Rocket Racoon tried to capture another alien named Gamora, who was trying to take the Cosmic Cube from a human named Peter Quill, aka Star-Lord. Their story, while exciting, is a work of fiction.

This is an undocumented immigrant. She's a mom,  a community activist for immigration rights, and a small business owner.

She came to America with her husband in the late '90s, and all three of her children were born here and are American citizens. Research shows that first generation immigrants commit less crime than native-born Americans. When it comes to second generation immigrants, the crime rate increases, but doesn't exceed the crime rate among native-born Americans, which makes sense, because a second generation immigrant was, most likely, born here.

This is a criminal alien. He's under serious arrest.

His name is Loki and he's both a frost giant and an Asgardian prince. He was arrested for throwing an epic temper tantrum in New York City and leaving billions of dollars of damage and destruction in his wake.

This is an undocumented immigrant. She's a child with a doll and brightly colored gloves.

Crossing the border is not a decision made lightly. People crossing the border illegally risk their lives, traveling however they can, often in overcrowded vehicles and across dangerous terrain trying to find a better life for themselves and their families.

So, what's my point here?

The point is that saying "criminal aliens" instead of "undocumented immigrants" invokes the subtle implication that immigrants are sub-human or, even worse, not human at all.

Fortunately, language can change and terms are fluid so it's important to point out the obvious distinction between aliens from outer space who wish harm to planet Earth and human people coming in from another country simply because they want a better life for themselves and their families.

Saying "undocumented immigrants" reinforces the notion that undocumented immigrants, whether they arrived in the country through legal means or not, are still human beings deserving of dignity and respect.

Using terms like "illegal alien," or worse, "criminal aliens," as freely as Mike Pence did during the vice presidential debate, only perpetuates the implication that individuals who are in the country illegally are not really people at all.

It's time to retire that hurtful and inaccurate descriptor. We are all from this planet and deserve to be treated as such.

And if anyone brings up these terms and you get confused as to which is which, feel free to pull up this handy guide for an instant refresher.