The phrase "to hack into" means to gain unauthorized access to a computer system or network. It usually refers to an act of breaking security measures in order to obtain information, manipulate data or perform other actions that are not allowed by the owner or administrator of the system. Hackers use various methods and tools to achieve this goal, such as writing code, using exploits, social engineering techniques or brute force attacks. The term "hacker" is often associated with malicious intentions, but there are also ethical hackers who try to find vulnerabilities in systems for the purpose of improving security measures.