Internet security consists of tactics to protect online activities from threats like hacking, malware, and identity theft. It focuses on vulnerabilities unique to using the internet, and is part of broader cybersecurity. Common threats include malware, computer worms, spam, phishing scams, and botnets. Choosing the right security tactics involves creating strong passwords, limiting social media oversharing, using caution on public Wi-Fi, watching for phishing links and attachments, and checking for website security features.