I fully admit this is over my head, but I was wondering if someone could give me the 30 second noob explanation as to what this is, exactly what it's written in and how would I convert this to ...

I'm working on a personal project where I need to write unsigned integers (UInt) to arrays of bytes, but in a special fashion. For example, I need to transform the uint, 675, into 2-bytes: 0x7506.