Patent management refers to the activities surrounding one's patents, from preparing and organizing them, to filing them officially. Patent management can be a very complicated task, depending on the particular type of patent involved - normally, experience/knowledge in law is required to some extent, which is why most people prefer to decide the details of their patents with the assistance of their lawyers. Additionally, good technical knowledge of the specific type of patent is very useful to those who perform patent management, as it allows them to more easily define the important details of the patent.
It's common for individuals without heavy experience in law to turn to companies for the purpose of managing their patents - which, while obviously useful in some regards, can also greatly affect one's potential earnings from their patent, and there have even been cases where legal disputes have arisen between a patent holder and the company responsible for their patent management. Sometimes, patent management companies are simply hired as advisors, providing an insight over the patent's possible outcome, and giving advise on how to better structure it to improve the chances of approval and the potential time required to process the patent.
Usually, in the case of a large-scale company, there would be an entire separate department dedicated to the task of patent management, receiving the various ideas that need to be submitted as patents from members of the company, and functioning as a middle man between them and the patent bureau.