There are three types of software you are likely to encounter whilst using your PC online. Spyware, adware and malware.
Most people use a collective term to describe them. Either a virus or spyware. Strictly speaking they are designed differently to perform certain functions.
Spyware.
Spyware does what it says. It spies on you. It can monitor your activities, surfing habits, credit card information, passwords etc. and send this data back to a central location so some unscrupulous people can use this data.
Unlike adware, spyware usually runs silently in the background without making you aware its there. Obviously the longer it goes undetected the more information it can retrieve from its victims.
Spyware is a very serious risk and should not be taken lightly. Once an attacker has got your personal details such as credit card information, passwords for online banking etc. you stand a very real chance of identity theft and financial loss.
Adware
Adware is generally used to force adverts in front of you. It will monitor your surfing habits and when you visit a site it recognises it will force a relative advert or pop-up.
Lets...