Avast Antivirus provides comprehensive protection against various online threats, including viruses, malware, and phishing attempts. It offers a free version with core features like real-time protection and automatic virus removal. Avast Premium Security adds advanced security features like ransomware protection, webcam protection, and data leak tracking. Additionally, Avast One is an all-in-one security and privacy solution that includes a VPN, and other features to enhance online security.