Re: What exactly is the edge?
When I was working at DEC, we were supplying systems that could, I guess, be considered a very early "edge" device in the 1980s. They were intended to collect data from a local store, do some aggregation and compression, and send the compressed data to HQ. The stores were not designed for computer installation - so any storage space with electrical power and reasonable air-flow would do. At least one of our computers was installed in a cabinet over the toilet in the (unisex) bathroom. Service required closing the bathroom and the tech standing on the toilet seat to work on the computer. There were some embarrassing incidents if a too, um, burly tech was sent to that job.
At DECUS (DEC User Symposium) conferences there was usually a midnight session where all the good stories were discussed. It was very hilarious and well worth staying up till near dawn.