FileReader

Good afternoon Please explain the FileReader action method. Does it read the entire line and then move on to the next one? Or by symbols? In this code: what exactly do the lines do: BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); BufferedReader fileReader = new BufferedReader(new FileReader(reader.readLine())); ArrayList lines = new ArrayList (); String line; while((line = fileReader.readLine()) != null) { int i = Integer.parseInt(line); lines.add(i); } String line; while((line = fileReader.readLine()) != null){}