it might sound very basic question but i need some help. I have lenovo Ideapad y560p which offers a maximum resolution of 1366px x 768px.

Now i am planning to buy an external monitor, and i short listed some FULL HD resolution monitors, but it is my understanding that even with FULL HD, i would only achieve the best resolution my laptop supports. Is it true?

And also if this is the case, should i really go for an HD monitor or settle down with a lower resolution version? 2ndly, is there any way to increase resolution with simple upgrade? or it is not possible without voiding the warranty??