So far the most general and convincing definition is to say that Web Services are the set of applications or technologies with the ability to interoperate on the Web. These technologies exchange data between them in order to offer services.
After installing your anti-virus, you must do the following to make sure that your computer will be virus free moving forward:
1. Scan every drive of your computer.
2. Scan every program, photo, video, etc before opening those.
3. Avoid visiting restricted sites.
4. Update your antivirus application. This way, the application gets new virus database.
5. Schedule antivirus scanning.
6. If your antivirus application do not have scheduled scanning, plan it.
7. Install antivirus widgets or extension in your web browser.
8. For maximum protection, you can install another antivirus application.
9. Uninstall risky applications.
10. Scan flashdrives before opening or exploing those. Avoid borrowing flashdrives.
11. Avoid inserting your flashdrives to other devices.
12. Defrag your system. Some virus can't be detected because your system's drive may be badly fragmented.