What is a batch system?
A batch system is used to monitor and control the jobs running on a system. It enforces limits on runtime (walltime) as well as the number of jobs running at one time (both total and per user). To run a job, the batch system allocates the resources requested in the batch script, sets up an environment to run the job in (thus running the users .cshrc and .login files), and then runs the job in that environment. In this environment, standard out and standard error are redirected into files in the current working directory at the time the executable is actually run.
