The tele in telecommunications is about voice or personal, person to person communications and the technologies that underlaid that. It started out with telephony and also some things around the edge of it like paging. It is fundamentally about people communicating. Then computers communicated, but that was called data communications, data comms. Those were two separate domains.
Telecommunications is actually has a specific regulatory meaning in a lot of countries. The ITU is a UN sponsored organization - the International Telecommunications Union. If you go back 40 years, you have this concept that every country had its PSTN, it's public switch telephony network. Telecommunications at that time was the domain of those national networks and how business or business users connected their premise systems to that standardized, governmental run network. Starting in the late eighties, you had the deregulation of telephony. It happened all over the world at different speeds. Fundamentally, what happened is, you ended up with competitive carriers introduced. Now, that has changed the whole world we live in, but when we talk about the word telecommunications and where it originates. It originates from that time when voice telephony and data communications were two different things. Now, telecommunications and data communications have converged.