Friendly acquisitions are most common and occur when the target firm agrees to be acquired; its board of directors and shareholders approve of the acquisition, and these combinations often work for the mutual benefit of the acquiring and target companies. Unfriendly acquisitions, commonly known as hostile takeovers, occur when the target company does not consent to the acquisition. Hostile acquisitions don't have the same agreement from the target firm, and so the acquiring firm must actively purchase large stakes of the target company to gain a controlling interest, which forces the acquisition.