Why IRLP is a Voice over Internet Protocol system that ties amateur repeaters and simplex nodes together over the internet, so audio from one repeater is carried as data packets to another repeater anywhere in the world. Each node has a four-digit number, and users key DTMF tones to connect or disconnect links. The RF part is still normal amateur radio; the internet only replaces the long-haul path between systems.
Watch out The choice about real-time notification of active DX stations describes a DX cluster or spotting network, which is a different internet-based tool; nothing in IRLP provides web browsing over ham radio.
IRLP = Internet Radio LINKING Project. The name says it: it links repeaters, it does not surf the web.