Adware is the least of your worries online, it’s the least malicious ‘ware’ of them all and very rarely has any serious consequences. As the name kind of suggests, it’s software that includes advertisements (ads) or collects marketing-type data from your searches to display ads that are related to what you like/visit on the web.
Adware is often spread via freeware or shareware. Similarly to spyware it can be bundled into freeware or shareware but most of the time this isn’t in a malicious manner. They are usually used as a legitimate way of generating advertising revenues to help fund development and