A computer virus is software code that acts similarly to a biological virus. The malicious code infiltrates the system and, by creating its own copies, leads to a mass infection of the computer. If the infected system communicates with other computers, it can also lead to infection. Thus computer viruses, like biological viruses, can cause digital epidemics.
The functions of computer viruses vary, but most often the malicious code destroys or corrupts data. In some cases, viruses slow down the system, and sometimes they can damage the hardware of a computer or server.
The ways of spreading computer viruses are very different: via e-mail attachments, by links in messages, through infected websites, by transferring USB drives, by embedding them in software that looks like legitimate software.
Antivirus software is a relatively effective protection against viruses, but it does not guarantee complete protection. To reduce the probability of infection, you should use only licensed software, do not visit sites with dubious content and do not open mail attachments from unknown recipients.
For commercial and industrial IT infrastructures implement comprehensive solutions and security policies that minimise the likelihood of malicious code penetration into the system.