Adware is a type of software that delivers ads on your system. Usually, these pop-up ads appear while visiting sites, like annoying pop-up ads or banners. They come in “bundle” versions with other applications. Most types of adware are not dangerous, maybe a bit annoying since they deliver pop-up ads while visiting a website, but there is another dangerous form of adware that delivers spyware, which can track down your activity and retrieve sensitive information. For this reason, users must not download an application from unsafe websites and pay attention to software that comes bundled. Less serious issues caused by adware can be slow-down problems or too many annoying pop-up ads that can fill your computer screen. Not to mention the stability issues which could affect your system. To remove malicious adware or spyware from the system, check online for specialized tools like Malwarebytes or Spybot.