When you need the power of an administrative user, you can access that functionality through a command called sudo, which will temporarily elevate the privileges of a single command.

By default, the Raspberry Pi is given an IP address by a DHCP server, which may change at each connection. In some cases this is not appropriate and a static IP address is preferable.

The Raspberry Pi does not include a hardware clock on board. It uses internet access to set the time with the help of NTP servers. Use of a hardware real time clock (RTC) allows the Raspberry Pi to be used without internet access and still provide services that use time stamps.

The serial port on the Raspberry Pi is configured as default for console input/output. To use the serial port with other programs and hardware such as modems, arduino boards etc. you need to disable the console login.

Using its own system SD card or an external USB drive as storage, the Samba server will provide NAS services to Windows clients.

Using the Raspbian WiFi configuration utility