For instance, the documentation that came with my Arduino kit has this schematic.
Pins 10 through to 13 are standard SPI pins on the Uno.
- 10 (SS)
- 11 (MOSI)
- 12 (MISO)
- 13 (SCK)
I have a tutorial here. I also have a Stack Exchange reference question and answer about SPI.
Most surprisingly, this tutorial doesn't even use the SPI pins at all.
It is certainly possible to "bit bang" SPI and in some cases this is desirable, for example if you have something like an SD card interface, and also want to use SPI for a display. On the page I linked, specifically at this post I describe how to bit-bang SPI.
What perplexes me the most is the sentence
The VCC and GND of the module go to the 5V and GND pins of the Arduino and the three other pins, DIN, CLK and CS go to any digital pin of the Arduino board.
For bit-banged SPI, yes you can use any pins.
Is this true? If yes, then what is the point of the SPI pins at all?
The hardware SPI is faster and easier, and you can do other things while SPI is sending/receiving but with bit-banging it is much more timing-dependent.