Which one of the following is not an application software?

Correct — D, Linker. Software divides into two broad kinds. Application software is written for the user's own purposes — writing, calculating, drawing, presenting — and it is what a person buys or installs to get a job done. System software exists to make the computer usable and to support the running of other programs; it includes the operating system, device drivers, and the toolchain of language translators and utilities. A linker belongs squarely in the second group. When a program is compiled, each source file becomes an object module with unresolved references — a call to a function defined elsewhere, or to a routine in a library. The linker takes those object modules and the libraries they need, resolves every external reference to a definite address, and produces one executable file that the loader can bring into memory. No end user ever opens a linker to do a piece of work; it is invoked by the build process. The other three options are all applications: a spreadsheet is a general-purpose tool for tabular calculation, AutoCAD is a computer-aided design package used by engineers and architects, and MS PowerPoint is presentation software. Note that the option list mixes a category with two products — 'spreadsheet' names a class while AutoCAD and PowerPoint are particular programs — but all three sit on the application side, so the mixture does not affect the answer.

• (a)Spreadsheet — Application software. A spreadsheet is a general-purpose tool for arranging data in rows and columns and computing on it with formulae — used by a person to do work, not by the system to build programs.
• (b)AutoCAD — Application software, and a specialised one — a computer-aided design package for drafting and modelling, used in engineering and architecture.
• (c)MS PowerPoint — Application software for preparing presentations, and part of an office suite. Being widely bundled with an operating system's vendor does not make a program system software.

System software manages the computer and supports the execution of other programs: the operating system, device drivers, and the language-processing toolchain of assembler, compiler, interpreter, linker and loader. Application software is written to perform tasks for the user: word processors, spreadsheets, presentation packages, design tools, browsers and media players. Utility programs — disk formatters, backup tools, antivirus — are usually grouped with system software. The dividing question is who the program serves: the machine and the programs running on it, or the person sitting in front of it.

The whole toolchain is worth holding in order, because the examiner sets questions on each link. An assembler turns assembly language into machine code. A compiler translates a whole high-level source program into object code in one pass over the source, while an interpreter executes the source statement by statement without producing a separate object file. The linker joins object modules and library code into a single executable and resolves the references between them. The loader then places that executable into main memory and starts it. Every one of these serves the production or execution of software, so every one is system software. When an option list is a mix of familiar user programs and one unfamiliar technical name, the unfamiliar one is very often the answer to a 'which is not an application' stem — but check the reason rather than the unfamiliarity, because the same trick is used in reverse with a system-sounding product that turns out to be an application.

• A linker combines the object modules produced by a compiler or assembler, together with required library code, into a single executable file.
• Its central task is resolving external references — matching a call in one module to the definition in another and fixing the addresses.
• The loader is a separate utility that brings the executable into main memory and begins execution.
• System software includes the operating system, device drivers, assemblers, compilers, interpreters, linkers, loaders and utilities.
• Application software includes word processors, spreadsheets, presentation packages, design tools such as AutoCAD, browsers and media players.
• The test for classification is whom the program serves — the machine and the software running on it, or the end user's own task.

• Assuming any well-known branded program is an application; some vendors ship system utilities under equally familiar names.
• Confusing the linker with the loader. The linker builds the executable; the loader puts it into memory and starts it.
• Treating an interpreter as producing an object file. It executes the source directly, which is why no separate linking step is needed.

As a which-one-is-not item like this one, as a straight definition of what a linker or loader does, or as a match between toolchain programs and their outputs.

No directly related past PYQ was found.

• practice — not a real PYQ

  The system program that brings an executable file into main memory and starts its execution is called which one of the following?

  • (a)Compiler
  • (b)Linker
  • (c)Loader
  • (d)Interpreter

  Answer(c) Loader — the linker produces the executable, and the loader places it in memory and begins running it.

• practice — not a real PYQ

  Which one of the following is NOT system software?

  • (a)Device driver
  • (b)Assembler
  • (c)Operating system
  • (d)Web browser

  Answer(d) Web browser — it is application software, run by the user to do a task, while the other three serve the machine and the programs on it.