Skyrocket is the name for the technology that supports Skynet's exceptional speed and efficiency. It is the Remote Procedure Call (RPC) designed from scratch to specifically support the needs of Skynet, consisting of three main components:
SiaMux — a high performant, custom connection multiplexer
Ephemeral Accounts — a packetized payment technique to decrease latency and boost bandwidth by prepaying hosts
Merklized Data Machine — an optimized virtual machine, enabling the execution of complex, dynamic programs on file contracts while providing cryptographic proofs for every instruction
Chris Schinnerl , Core Developer at Skynet Labs, has written wonderful guides outlining each component.
Reducing Latency 96% by Switching P2P Platform Skynet to a Multiplexer
Optimizing Payment Channels to Achieve CDN Latencies (Skyrocket Part 2)