Distributed systems (multiple computers working together over a network) bring significant challenges that don't exist in single-machine systems — network unreliability, partial failures, consistency, coordination, and more. Understanding these is essential for designing systems at scale.
Why distributed systems are hard
Multiple machines communicating over a NETWORK introduce fundamental challenges:
→ the NETWORK is unreliable (latency, packet loss, partitions) and not instant
→ PARTIAL FAILURES → some parts fail while others work (vs all-or-nothing on one machine)
→ no shared memory/clock → coordination is hard
→ "the network is reliable" etc. are FALLACIES — distributed systems break these assumptions.
