The phrase "to hook into" means to become connected or integrated with something else. It can refer to connecting a new system, program, or device to an existing one in order to take advantage of its capabilities or functions. For example, when a company wants to use the services of another company for their business operations, they may need to "hook into" that other company's systems and processes so that both companies can work together seamlessly. In essence, it means establishing a connection between two things in order to make them work together.