They have meaning, it's not right or wrong, it's how you tell the interpreter how to read your code.
You use curly braces to group statements into a single statement which is executed together. For example, a function's statements are all grouped together by curly braces.
So, if you're wondering how they should be placed, you'll have to decide how they're supposed to be grouped and place the braces accordingly.
If you indent based on the braces in the code you posted above, you'll get:
return "The result is a tie!"
if (choice2 === "scissors")
return "rock wins"
return "paper wins"
return "paper wins"}
return "scissors wins"
See how there are a couple of them missing in the end, how the code is far to the right but there's nothing that closes those scopes