AdBlock is an anti-adware freeware extension for search browsers that blocks advertisements, which stops adware from coming in the first place. It also can also block malware in the settings, making it a useful tool.
While being a helpful tool, it is also criticized for 'damaging the internet', as websites rely on ads to make money, and with AdBlock, it will cut the revenue. It also stops YouTubers from getting money off of the ads. Many people like NISLT have made videos about the advertisement blocking tool, and how they want people to stop using AdBlock.