The term CPE can mean a lot of different things. By itself, it means “Customer Premises Equipment.” That’s a pretty generic term.
“CPE” usually refers to professionally installed equipment that is owned by a third party like a phone company but is installed on the customer site. Think about the network terminal provided by your internet company. That’s a perfect example of CPE. The term is also used to refer to any high-end industrial equipment no matter who owns it. For example, large Wi-Fi antennas or cellular repeaters are sometimes referred to as CPE.
The real heart of the idea of CPE is that you, the average person, aren’t supposed to touch it. You’re supposed to consider it part of the infrastructure of your home or office, something only the professionals work on, because it’s not designed to be user-friendly. This makes the idea of CPE a little bit of a copout… it seems to actually mean something that doesn’t have a user manual and that is way too hard to understand.
So the real message here is that if you see something labeled CPE and you’re not an installer or really savvy DIY’er, hire someone who is.