When you first turn on your Mac (or install an upgrade to the operating system), a series of questions and prompts appear, including a prompt to sign in to your Apple ID account or create a new Apple ID.An Apple ID identifies you and your devices in all things Apple that you do: registering new products, purchasing media and apps from the iTunes Store, the Book Store, and the App Store, as well as signing in to your iCloud account.

iCloud remotely stores and syncs data that you access from various devices — your Mac and other Apple devices, such as iPhones, iPads, and iPods, and PCs running Windows. Sign in to the same iCloud account on different devices, and the data for activated apps syncs; that is, you find the same data on all your devices, and when you make a change on one device, it shows up on the others.

Safari and iCloud have terrific built-in features that help you remember user names and passwords and credit card information. And Safari has security and privacy features to keep that personal information to yourself — or to your Mac. Here, we tell you how to use AutoFill so Safari remembers passwords for you, and then we explain how to keep your information safe.

Many people consider passwords to be less than ideal for security. To begin with, you have to remember them. The only sure way to make sure you don’t forget or lose your password is to write it down and keep that piece of paper (or whatever you wrote on) safe.There’s a better way if you have a current MacBook Pro or MacBook Air that supports Touch ID.

Catalina’s built-in software firewall acts as the wall surrounding your MacBook castle by allowing in the communications you want while preventing unknown communications from potential threats. The Catalina firewall works with your Internet connection and with any networks you may have joined.To display the Firewall settings, click the System Preferences icon on the Dock and then click the Security & Privacy icon.