Adware (engl. advertisement; software) are programs that automatically display advertisements on a computer.
As soon as such a program is installed on a device it starts displaying all different kinds of advertisements like pop-ups, banners etc. In this case, the term adware is used as a synonym to malware – a software that displays unwanted content. Mostly, users install such a software accidentally on their mobile devices when downloading any kind of free software from the internet.
Since it is usually coming bundled in with other software, most users don’t even recognize they installed adware on their smartphone or computer. In fact it can be quite dangerous because it poses a threat to a user’s personal data and information. As the collected user information is sent over the internet, it is easily accessible for hackers.
Another indication of adware is that it has the ability to severely slow down the performance of a smartphone or computer.