Application software
Programs designed for an end user to do a particular task,such as word-processing and spreadsheet,programs
Application software enables the computer to do a particular task,such as word processing
System software
Includes the operating system and all utility programs that enable the computer to operate its hardware and applications software
System software:
- Is the interface between computer hardware and user application
- Enables the computer to operate its hardware and applications software
- Includes the operating system and utility programs
Real-Time processing
Processing of data occurs immediately after data is input and updating occurs before the next input occurs
Applications which use real-time processing include:
- Airline/concert booking systems
- Online stock control systems
- Air traffic control systems
Batch processing
Data is collected over a period of time,such as a day,and is processed together at later time,such as overnight
Applications which use batch processing include:
- Billing systems (e.g. electricity/gas/telephone)
- Payroll systems (on a weekly on monthly basis)
- Banking systems (producing monthly customer statements)
Multi-user system
It involves many users at different computers each sharing a processor.The operating system switches between computers,giving each one a ‘time slice’
Applications which use Multi-user systems include:
-Multi-user database management systems
Utility application
A program that preforms a very specific task in managing system resources,such as a backup program
Disc defragmentation
- Rearranges the data stored on a hard disc so that files are stored in adjacent blocks
- All the free blocks (free storage space) are together in the same part of the disk
- Speeds up the time it takes to access files because all the data is stored in the same area of the disk
Task scheduling
- Processor time is divided amongst a number of tasks
- Uses time slices
- Implemented using a ‘round robin’ method
Data backup and restore
-A second copy of a file made and stored on a different storage device in case the original file gets lost,or becomes corrupted or physically damaged
Backup is used to restore data to its original state
Virus
- Its main purpose is to detect,locate and remove a virus that can infect a computer system
- A virus is a program that can attach itself to a file and then spread to other files
- A virus can intentionally damage a computer system,prevent it from booting up or slow down the performance of a computer
- Scans
Role of anti-virus software
- Its main purpose is to detect,locate and remove a virus that can infect a computer system
- Anti-Virus software scans files stored on a computer and data entering a computer system,and compares these to a known database of viruses
- The software can scan all storage devices connected to a computer,such as the internal hard drive,USB memory pens and so on
