The Free On-line Dictionary of Computing (30 December 2018):

utility software
utility
utility program

    (Or utility program, tool) Any software that performs
   some specific task that is secondary to the main purpose of
   using the computer (the latter would be called application
   programs) but is not essential to the operation of the
   computer (system software).

   Many utilities could be considered as part of the system
   software, which can in turn be considered part of the
   operating system.

   The following are some broad categories of utility software,
   specific types and examples.

   * Disks

   disk formatter: FDISK, format

   defragmenter

   disk checker: fsck

   disk cleaner

   system profiler

   backup

   file system compression

   * Files and directories

   list directory: ls, dir

   copy, move, remove: cp, mv, rm, xcopy

   archive: tar

   compression: zip

   format conversion: atob

   comparison: diff

   sort: sort

   * Security

   authentication: login

   antivirus software: avast, Norton Antivirus

   firewall: Zone Alarm, Windows firewall

   encryption: gpg)

   * Editors for general-purpose formats (as opposed to specific
   formats like a word processing document)

   text editor: Emacs

   binary editor, hex editor

   * Communications

   mail transfer agent: sendmail

   e-mail notification: biff

   file transfer: ftp, rcp, Firefox

   file synchronisation: unison, briefcase

   chat: Gaim, cu

   directory services: bind, nslookup, whois

   network diagnosis: ping, traceroute

   remote access: rlogin, ssh

   * Software development

   compiler: gcc

   build: make, ant

   codewalker

   preprocessor: cpp

   debugger: adb, gdb

   installation: apt-get, msiexec, patch

   compiler compiler: yacc

   * Hardware

   device configuration: PCU, devman, stty

   (2007-02-02)