Astroturfing is the deceptive practice of making a coordinated campaign look like a genuine, organic groundswell of public opinion — the name is a pun on "grassroots". A company, government, or political group manufactures the impression that many independent people spontaneously share a view, when in reality the messages are centrally directed and often paid for. It is a form of disinformation aimed not at a single false fact but at faking consensus.
Online, astroturfing usually relies on fake accounts, paid posters, and bots, which makes it a common expression of coordinated inauthentic behavior. Investigators expose it by finding the seams: near-identical wording repeated across "independent" voices, suspicious account-creation dates, or funding trails that connect supposedly separate groups back to a single sponsor.