No semicolons

In Java, every line of code must be terminated with a semicolon:

System.out.println("Hello"); //<- This is a semicolon
System.out.println("World"); //<- I still see you, semicolon

But Kotlin is a pragmatic language. So, instead, it infers during compilation where it should put the semicolons:

println("Hello") //<- No semicolon here
println("World") //<- Not here

Most of the time, you won't need to put semicolons in your code. They're considered optional.