Nothing lasts forever, like every other machines even satellites go through a phase when they stop working. Satellites give a lot of information on weather, they measure greenhouse gases in the atmosphere and can also tell you about stars and objects that are far away from Earth.
But what happens when a satellite time has come and it falls on Earth? Usually, satellites that are no longer functioning and spacecraft burn up while entering the Earth's atmosphere. However, some large satellites or space stations do not completely burn up before reaching the Earth's surface.
For such big satellites, spacecraft operators can plan their final destination to land them in a remote area in the Pacific Ocean, called Point Nemo or Spacecraft Cemetery to make sure that any debris falls into that specific remote area. Pacific Ocean is quite much the farthest place from any human civilization you can find.