For Palestinian residents of the West Bank, Jerusalem contains major organizations, services, and markets that are not available in the areas where they live. The table below lists some of the more important ones. In Organizations on the Ground, you can find many more.
People with Palestinian Authority (PA) identity cards cannot enter Jerusalem without an approved entry permit from the Israeli Coordination of Government Activities in the Territories (COGAT). Even if they are able to obtain a permit, the conditions listed for allowed entry will likely restrict them only to one destination per entry. So if they need to visit multiple, they will likely have to reapply for multiple entry permits. And even if they obtain a permit allowing them to go to a hospital, for example, the allowed time window will be only very short, like a few hours.
Thus, preventing millions of people from accessing Jerusalem means depriving them of all kinds of essential care and resources that often can mean the difference between life and death.