Lightning strike. A lightning strike is an electric discharge between the atmosphere and an earth-bound object. They mostly originate in a cumulonimbus cloud and terminate on the ground, called cloud to ground (CG) lightning.
Virus protection software is designed to prevent viruses, worms and Trojan horses from getting onto a computer as well as remove any malicious software code that has already infected a computer. Most virus protection utilities now bundle anti-spyware and anti-malware capabilities to go along with anti-virus protection.
Antivirus software is all about prevention. It is used to prevent files that contain viruses from being downloaded onto your computer. It also tries hard to prevent the virus from being activated, should it somehow get downloaded to your computer, placed in memory or in a file-like location.