On-demand scanning is a feature of both Anti-Virus and Anti-Spyware scanners. Real-time protection is much better from a security standpoint, but it consumes more system resources than an on-demand-only program.
- Real-time Protection - The system is constantly protected.
- On-demand - Most Anti-Virus and Anti-Spyware programs include on-demand scanning. This type of scanning is initiated by the user and not the software. Otherwise known as a manual scan.
- On-demand-only - Some shareware, freeware and open source scanners are on-demand-only. This means that it does not offer real-time protection.