I got it from this article:
Protocol Buffers often abreviated Protobufs is the format use by TF to store and transfer data efficiently.
To recapitulate, you can use Protobufs as:
An uncompressed, human friendly, text format with the extension .pbtxt
A compressed, machine friendly, binary format with the extension .pb or no extension at all
I am semi-familiar with android software and am able to transfer already trained models to my phone but in order for me to use my own trained model I need to be able to save my model in that format. I have been able to save it using tensorflow but it doesn’t work on my phone and its difficult to debug why.
With the in class lessons and forums I have been able to understand your code far better so would be able to debug more effectively hence the need to save in that format.