To install macOS Catalina (10.15), there are three methods. Standard installation of the update if your Mac is compatible with macOS Catalina, the dual boot macOS Catalina/ macOS Mojave (a system in main partition and another on a second partition or on an external disk) and finally the clean installation on a new formatted disk, and, as a bonus, the virtualization technique for muscle configurations. We will describe in this post the Standard installation of the update.
INSTALLING MACOS CATALINA (10.15): SOFTWARE UPDATE
Most users will choose the update of macOS Mojave to Catalina. This will install the new macOS Catalia (10.15) over the old macOS Mojave (10.14.6), for example. You will keep your Office, your files, your documents as such. But, before you start to migrate, we strongly recommend you perform a Time Machine backup on an external disk (Choose an external disk for Mac: SSD, hard disk, USB 3.0, USB-C, Wifi, Thunderbolt)or better yet, cloning your Mac disk on an external disk.
Go to the Apple menu , System Preferences… and click the Software Update icon.
Just click the Upgrade button now, wait for the download time.
You will then see the Catalina installation window start automatically.
You will choose to install macOS Catalina on your main partition named Macintosh HD, macOS, etc. ), then you will logically click on Install! All you have to do is cross your fingers…