What is difference between console.readLine() and Scanner?

Question

My teacher is using Console.ReadLine(), but I've learned to use Scanner.

int age = console.readLine("age: ");

and

System.out.println("age: ");
int age = scan.nextInt();

1. What is the difference between these?

2. Is it possible to write scan method in one line like readLine?

3. How can I use console on IDES?