Hardware and software study guide

Build the conceptual model

Start with the relationship between the two basic categories. Hardware is the physical machinery, including processors, memories and I/O devices. Software is the programs that control or use that machinery. A useful exam explanation is not merely that they are different: software needs hardware on which to operate, and hardware needs software instructions to perform useful processing. This relationship explains why system software is needed between hardware and application software.

Classify from purpose

When given an unfamiliar program, identify its purpose before naming its category. If it supports the operation or management of the computer system, it is system software. If it is designed to perform a particular task for the user, it is application software. Explain the classification rather than relying on the program's name. The distinction is about purpose and required attributes: system software must support access to and management of the system, while application software must provide the functions of its intended application.

Explain the OS as an abstraction and manager

A strong answer should connect two roles. First, the OS hides the complexities of the hardware. This means that other software can work through the services provided by the OS instead of dealing directly with every hardware detail. Second, the OS handles resource management. It manages hardware by allocating processors, memories and I/O devices among competing processes.

For example, if multiple processes require access to a processor, memory or an I/O device, they are competing for a hardware resource. The OS is responsible for managing the allocation between them. The reasoning chain is: multiple processes create competition; hardware resources must therefore be coordinated; the OS performs that coordination; this both manages the resources and hides their complexity from other software. Avoid adding unsupported detail about a particular allocation algorithm unless the question supplies it.

Distinguish the named system software

An operating system manages resources and hides hardware complexity. A utility program supports system operation or management. A library supplies reusable software components. A translator changes a program from one form into another. Compilers, assemblers and interpreters are all named types of translator, so do not treat them as alternatives to system software; they are types within the translator category.

Self-check questions

1. Define hardware and software, then explain how they depend on one another.
2. Given a program description, justify whether it is system software or application software.
3. Explain why an OS is needed when several processes compete for processors, memories and I/O devices.
4. State how hiding hardware complexity is connected to resource management.
5. Distinguish an OS, a utility program, a library and a translator.
6. Name the three translator types in the specification.

For each answer, use the terms system software, application software, operating system, resource management, process, processor, memory and I/O device accurately. Check that every explanation gives a reason or relationship, not just a list of terms.