Let's see how to update and upgrade Raspbian:

1. First, update your system's package list by entering the following command:

pi@raspberrypi:~ $sudo apt-get update

Refer to the following screenshot:

2. Then, upgrade all your installed packages to their latest versions with the following command:

pi@raspberrypi:~ $sudo apt-get dist-upgrade

3. When prompted, press Y to continue: