I have read the spec sheet on the uno and it offers 5v from the 5v pin.
(I have used it for switches and pots)
I want to transfer my setup to a nano because its smaller but i’m not too sure if the 5v pin (pin 27) on the nano has the same function. I have read the spec sheet for the nano but can’t find any reference to it other than it can be powered through pin 27 with 5v.
Can anyone shed some light on this for me please?
Yes, the 5v pin is tied directly to the 5v power rail; meaning that if the board is powered (via USB or a 7~12v supply on the Vin pin, which the nano inexplicably calls "RAW"), there is 5v on the 5v pin and you can use it to power external devices.
You can also power it with an external 5v supply connected to that pin, but this isn't advisable, because if another power source is connected (for example, if it's plugged into USB), the two supplies are not prevented from fighting with eachother over exactly what 5v is, and this can damage the board.