What is the difference betwen a "messenger" and a "courier"

My memory is getting foggy with age. I can remember seeing motorcycle couriers in or around 1980. I also remember doing some research into the Post Office monopoly in 1975 or 1976.

Maybe they only had a monopoly on certain streets, perhaps the green set or the dark purple set?

[QUOTE]Now you mention it, however, I also recall people I knew in the late 1970s working as motorbike couriers. They used to hang around phone boxes as they often weren't given (or possibly allowed) radios.

Why did they hang just for not having radios? That seems excessively cruel to me.

I am old and my memory is suspect.

Yes, it all sounds a bit strange.