What are experts in technology who use their knowledge to break into computers and networks, for profit or just as a challenge known as?

Hacker

Explanation:

Hacker -

It refers to the computer software expert , who is responsible to break into the unauthorized networks or computer , is referred to as a hacker .

The hacker is skilled with exceptional computer and computer software knowledge .

Hacking is an illegal practice , as the person is able to access some confidential and personal data and information of any other person or organisation .

Hence , from the given information of the question ,

The correct term is hacker .