Abstract factory Builder

Question

Below is my Builder pattern class which generates an Employee Object.

public class Employee {
    // required parameters
    private String HDD;
    private String RAM;

    // optional parameters
    private boolean isGraphicsCardEnabled;
    private boolean isBluetoothEnabled;

    public String getHDD() {
        return HDD;
    }
    public String getRAM() {
        return RAM;
    }
    public boolean isGraphicsCardEnabled() {
        return isGraphicsCardEnabled;
    }
    public boolean isBluetoothEnabled() {
        return isBluetoothEnabled;
    }

    private Employee(EmployeeBuilder builder) {
        this.HDD=builder.HDD;
        this.RAM=builder.RAM;
        this.isGraphicsCardEnabled=builder.isGraphicsCardEnabled;
        this.isBluetoothEnabled=builder.isBluetoothEnabled;
    }

    public static class EmployeeBuilder {
        private String HDD;
        private String RAM;

        // optional parameters
        private boolean isGraphicsCardEnabled;
        private boolean isBluetoothEnabled;

        public EmployeeBuilder(String hdd, String ram){
            this.HDD = hdd;
            this.RAM = ram;
        }

        public EmployeeBuilder isGraphicsCardEnabled(Boolean isGraphicsCardEnabled){
            this.isGraphicsCardEnabled = isGraphicsCardEnabled;
            return this;
        }

        public EmployeeBuilder isBluetoothEnabled(boolean isBluetoothEnabled){
            this.isBluetoothEnabled = isBluetoothEnabled;
            return this;
        }

        public Employee build(){
            return new Employee(this);
        }
    }

    public static void main(String args[]){
        Employee emp = new Employee.EmployeeBuilder("500", "64").
                isGraphicsCardEnabled(true).
                isGraphicsCardEnabled(true).build();

        System.out.println(emp.HDD);
        System.out.println(emp.getHDD());

    }
}

A builder whose parameters have been set makes a fine Abstract Factory [Gamma95, p. 87]. In other words, a client can pass such a builder to a method to enable the method to create one or more objects for the client. To enable this usage, you need a type to represent the builder. If you are using release 1.5 or a later release, a single generic type (Item 26) suffices for all builders, no matter what type of object they’re building.

Can anyone add some light on the above paragraph with an working example. I am not able to understand the above para which is taken from Effective Java - Joshua Bloch.