Beginning with to understand what a virus is we will start with the original biological meaning of the word. Biological viruses like the ones that can make you sick are parasitic. They inject their code in this case either DNA or RNA into a host cell as a means of replication this code causes the cell to make a ton of copies of the virus and ultimately burst to send new viruses everywhere. Computer Viruses operate via a similar principle unlike some forms of malware which are fully executable programs. Viruses tend to be smaller pieces of code that confused with other programs or files and only replicate when conditions are right. So they can be triggered by a particular date and time opening a certain program or even hitting a certain amount of disk usage. After a virus is triggered, it will try to copy itself and spread infecting other files and programs along the way sometimes over a network and just like real viruses these virus copies can be a little different from the original making it hard for antivirus software to eliminate them. Some even come encrypted making detection even more complicated. Also, read How to Install iOS 11 Public Beta on iPhone and iPad A computer virus can contain a payload that will cause some effect which could be anything from just displaying a joke to permanently corrupting your important data. To make it simple now, Malware is any computer infection, which includes viruses and malicious software. Since other types of malware can cause these annoying effects, many people have used the terms virus and malware interchangeably, but this is incorrect. Much modern malware like ransomware and adware are also standalone programs that can be passed around and executed on their own.
