Indicates resemblance or a metaphorical comparison in actions or objects
Example
그녀는너같이예쁜다.
She is as pretty as you.
로봇같이걷다.
Walk like a robot.
영화배우같이잘생겼어요.
He is handsome like a actor.
같이 as adverb
Note that 같이 also exists as an adverb. In this case, it is used to express that an action is performed with someone else. Often accompanied with the particle N+와/과.
촛불을켜고같이생일축하노래를불렀어요.
We lit the candles and sang the birthday song together.