나란히 앉다 (na-ran-i an-da) – to sit side by side
This phrase can be used to describe how people sit beside each other in business meetings or social gatherings.
I believe we can use this phrase to describe how inanimate objects are positioned beside each other too, but you would probably use 놓이다/놓여 있다 (to be placed) instead of 앉다 (to sit).
Most importantly, just understand that 나란히 means “side by side”.
그 두 사람은 카페에서 나란히 앉으면서 얘기도 하니 사이가 너무 좋아 보이네.
That two people are sitting side by side at the cafe while chatting, their relationship looks very good.
우리 아빠는 티비를 볼 때마다 누가 나란히 앉아도 모르셔요.
Whenever my Dad watches TV, he wouldn’t even know if anyone is sitting side by side with him.
And an extra example for the variation of 나란히 coupled with another verb.
내 강아지는 침대 위에서 놓이는 곰 인형과 나란히 누우면 너무 강아지 인형과 같네.
If my puppy were to lie side by side with my teddy bear plush on my bed, it really looks like a puppy plush.