Computer Software and Language Translators
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Key points
- System software runs the machine; application software does a user task
- Device drivers and operating systems are system software
- Compiler translates the whole program; interpreter works line by line
- Assembler converts assembly language into machine code
- A loader places a program in memory and does not translate
- Freeware is free but not necessarily open source
Two main types of software
| Type | Purpose | Examples |
|---|---|---|
| System software | Runs and manages the computer itself | Operating systems, device drivers, utilities, translators |
| Application software | Does a specific job for the user | MS Word, MS Excel, Tally, Photoshop |
Key point
A device driver is system software even though it serves one device. Windows, Linux and macOS are system software; Excel and Tally are application software.
Language translators
| Translator | How it works | Error reporting |
|---|---|---|
| Compiler | Translates the whole program at once | Lists all errors together at the end |
| Interpreter | Translates and runs line by line | Stops at the first error |
| Assembler | Converts assembly language into machine code | Works only on assembly language |
A loader is not a translator. It only places a program into memory so it can run.
Software by licence
- Freeware: free to use, but the source code is not necessarily available.
- Shareware: free for a trial period, then payment is required.
- Open source: the source code is available under an open licence, such as Linux and LibreOffice.
- Proprietary: owned and licensed by a company, such as MS Office.
Example
A program can be free of cost and still be closed. That is why the statement Freeware always provides its source code is false, and it appears as a distractor very often.
Exam tip
Statements containing always, only or never are usually false. Test the word before you test the fact.
Practice questions
Answer all, then check. Explanations appear after checking.
Finished this topic? Tick it off.
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