What is an amateur radio station that connects other amateur stations to the internet?
Why A gateway is the bridge point between RF and the internet: it receives signals on the amateur bands and passes the traffic onto an internet-linked network (and vice versa). Examples include IRLP/EchoLink nodes, D-STAR and DMR hotspots, APRS internet gateways (I-gates), and Winlink RMS stations. The word itself is the clue, it is the 'gate' between two different kinds of networks.
Watch out A repeater simply retransmits signals on RF within its coverage area, and a digipeater does the same digitally by storing and forwarding packets; neither touches the internet unless it also has a gateway function attached. A beacon just transmits one-way for propagation study.
Gateway = gate between RF and the internet. Repeater and digipeater stay on the air.