Spyware/adware are those software which send your personal data like, your browsing behavior, your computer's system configuration, Software installed on your computer and a lot of other information depending on the nature of the spyware, to their companies without your or knowledge.It is virtually impossible to avoid them since they are very clandestine in nature and get hardly noticed by a user.The data sent by them can be harmful for your privacy as it may include your address, email and other personal information.