Here’s how it happens. You go online with your nice, well-behaved browser, only to see it flying into a virtual tantrum, as an onslaught of advertisements either pops up, slides in from the side, or otherwise inserts itself to interrupt and even redirect your intended activity. And no matter how much you click to close those windows, they keep buzzing you like flies at a picnic.

That bothersome phenomenon results from adware, short for advertising supported software. And just as your picnic food attracts the pests that come after it, money—or the revenue generated by unbidden ads is what draws adware to your PC or mobile device. Below, we offer a short primer on adware,

 that it is, how you get it, that can help you, how to deal with it, and what to do in the future to the point of avoiding the irritant.

What is adware?

Adware is unwanted software designed to throw advertisements up on your screen, most often within a web browser. Some security professionals view it as the forerunner of the modern-day PUP (potentially unwanted program). Typically, it uses an underhanded method to either disguise itself as legitimate, or piggyback on another program to trick you into installing it on your PC, tablet, or mobile device.

Adware generates revenue for its developer by automatically displaying online advertisements in the user interface of the software or on a screen that pops up in the user’s face during the installation process. And that’s when you start seeing dubious miracle weight loss programs, offers for get-rich-quick secrets, and bogus virus warnings that requires a click. Also, you might experience new tabs opening, a change in your home page, finding from a search engine you never used before, or even a redirect to a NSFW website.

Keep it well, preferably that legitimate software applications do use online advertising, with Ads that are typically bundled within the program, that display the ways of the program which the developer has specified. Adware is an altogether different kettle of rotten fish. You might download it without understanding its intent. Or it might land on your PC by means of legitimate software within which it’s secretly buried. Whatever the path, it all boils down to some program on your computer showing you advertisements that do not come from the websites you are visiting.