In all the projects and explanations I will use various terms to identify the same thing.
In particular I could mention -, 0V, negative pole of the battery, ground, GND and Vss.
Those all mean the negative pole of the battery that is at 0V.
On the other side of the spectrum I mention +, Vcc, Vdd or positive pole.
This refers to the positive pole of the battery which exact value will be different depending on the battery or power source used: 9V, 3.3V, 5V, and so on.
Why so many terms? Different families of electronic components adopted different acronyms:
- TTL (Transistor-Transistor Logic) components use
VccandGND. - CMOS (Complementary Metal-Oxide-Semiconductor) components use
VddandVss).
More electronics tutorials:
- Electronics Basics: using a multimeter
- Electronics Basics: Prototyping using breadboards
- Arduino project: read a digital input
- Electronics Basics: Voltage
- The Arduino Uno rev 3 board
- The Arduino Uno WiFi rev 2 board
- Electronic components: Analog Joystick
- Arduino vs Raspberry Pi
- Electronics Basics: Current