Viral phenomena are objects or patterns able to replicate themselves or convert other objects into copies of themselves when these objects are exposed to them.

The concept of something, other than a biological virus, being viral came into vogue just after the Internet became widely popular in the mid to late 1990s. An object, even a non-material object, is considered to be viral when it has the ability to spread copies of itself or change other similar objects to become more like itself when those objects are simply exposed to the viral object. This has become a common way to describe how thoughts, information and trends move into and through a human population. Memes are possibly the best example of viral patterns.

Examples of viral phenomena in addition to memes are:

• Viral marketing
• Clothing fashion trends
• Viral email
• Viral recommendations
• Blogging
• Software licenses (such as the GNU General Public License)

See also

• Computer virus
• Memes