Key Difference: Adware or advertising-supported software is a software package that automatically renders advertisement for the company that pays to have its advertisements displayed. Spyware, true to its name is software that spies on shopping and browsing habits of users.

It is a safe bet to say that technology has made us lazy. The internet is where we go to shop now, Wii is where we get our exercise and well everything else is history. These days you can even get the grocery shopping done online, amazing isn’t it?  However, these technologies also bring software that we don’t want snooping around our lives, this is what adware and spyware are. These are different software that are unwanted but are still a part of our tech world.

Adware or advertising-supported software is a software package that automatically renders advertisement for the company that pays to have its advertisements displayed. The ads are in two forms either in the user interface of the software or on the wizard during installation. Adware can also be included as a pop-up, where clicking a link would activate the pop-up. The purpose is to make the user aware of such website and it generates money for the company when a user clicks or goes on to the website.

In legitimate software, the advertising software is bundled up with the program. Some companies may also offer users a trial version of the software that lasts a limited amount of time, after which the user has an option to purchase the software. Adware is usually seen by the developer as a way to recover development costs of the product. Some software is offered in both an advertising-supported mode and a paid, advertisement-free mode. Companies such as Skype, Kindle and many apps offer a free version with advertisements, but offer customers an ad-free version after purchasing the application. The term adware is also frequently referred to as malware (malicious software), which usually present unwanted advertisements. Some pop-ups can also be linked with viruses that a user may accidently install if he clicks on the advertisement.

Spyware, true to its name is software that spies on shopping and browsing habits of users. A spyware that is installed on a computer is considered as a potential threat because it can use personal information by the user and provide them to advertising companies. The software is responsible for gathering information about a person, without the person’s knowledge and sending the information to a third party without the consumer’s content. "Spyware" is mostly classified into four types: system monitors, trojans, adware, and tracking cookies. On its website Microsoft defines ‘spyware’ as, “Spyware is often associated with software that displays advertisements (called adware) or software that tracks personal or sensitive information.”

Spyware is most commonly used to track the user’s interests and then using them for rendering pop-up ads to the user. Some spyware such as keyloggers is installed by companies in order to keep an eye on their employees. Spyware can become malicious when it targets personal information such as social security numbers, credit card numbers, username and passwords. People can detect and remove spyware using free tools that are available online or by installing security programs. Some spyware can also be integrated into shareware and freeware. For installation, spyware uses the loopholes in JavaScript, Internet Explorer and Windows operating system itself. 

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