title: Does a process need a system call for accessing memory such as files, local memory on RAM?
body: <p>Whenever we open a program and choose dialog box (say for libre office) for selecting a file, We are actually traversing the file structure of the hard disk. But is that a system call?. if it is, then isn't that too much switching back to user and kernel modes as you click each folder which will make user interactive processes slow.?</p>
  
  <p>What about the local memory which is loaded for a process. Does it need system call for accessing that?</p>