Terminology

681 terms, tools, patterns and metrics an architect is expected to use precisely. Each one gets a short explanation of what it is, and — where it matters — what it is commonly confused with. Search filters as you type; the column headers sort.

All areas681 Architecture Fundamentals38 Distributed Systems73 Data Architecture71 Cloud Architecture55 Networking51 API & Integration Architecture45 Reliability & Resilience40 Observability33 Performance & Capacity Engineering34 Security Architecture50 Cost Architecture & FinOps12 Business Architecture9 Architecture Communication8 Enterprise Architecture8 Legacy Modernization11 AI-Era Architecture34 Software Architecture & Engineering37 Architecture Patterns34 Architecture Decision-Making30 The Architect's Meta-Skills8

Kind Any concept258 practice180 pattern127 protocol32 tool32 case-study26 metric26

258 terms shown.

Term	Kind	Topic	What it is
Two-Way Door	concept	Reversibility	A decision that can be undone cheaply, and which therefore warrants a fast decision by the people closest to the work rather than extensive analysis.
Utilisation and Queueing Delay	concept	Queueing Theory	The non-linear relationship by which waiting time grows as utilisation approaches one, explaining why systems degrade suddenly rather than gradually.
Value Stream	concept	Business Architecture	The end-to-end sequence of activities that delivers a result to a customer, viewed across whatever departments and systems it happens to cross.
Vendor Lock-In	concept	Technical Constraints	The cost of switching away from a provider, treated as a quantity to be managed deliberately rather than a condition to be avoided absolutely.
Version Vector Vector Clock	concept	Clocks & Ordering	A per-replica counter set that lets a system tell whether one version causally descends from another or whether the two are genuinely concurrent.
View Staleness Window	concept	Materialized Views	The maximum age of data in a precomputed view, which must be an explicit, monitored contract rather than an incidental property.
Virtual Private Cloud VPC, VNet	concept	Networking	A logically isolated network inside a cloud provider, with an address range you control and explicit rules for what may enter and leave.
Visibility Timeout	concept	Messaging & Queues	The period after a consumer receives a message during which it is hidden from other consumers, before it becomes available again for redelivery.
VPC Peering	concept	VPC Design	A direct network connection between two VPCs, which is simple, cheap and non-transitive — the last property being the one that shapes topology.
VPN vs Dedicated Connection Direct Connect, ExpressRoute	concept	Private Connectivity	Two ways to link on-premises networks to cloud — an encrypted tunnel over the internet, or a private physical circuit.
Watermark	concept	Streaming Data	A moving assertion that no events older than a given event-time will arrive, which is what allows an event-time window to be closed and emitted.
Webhook Retry Policy	concept	Webhooks	The provider's schedule for re-attempting failed deliveries, and the contract the receiver must be built against.
Windowing	concept	Streaming Data	Grouping an unbounded stream into finite chunks so aggregation can produce results, defined over event time rather than arrival time.
Write Skew	concept	Transactions & Isolation	An anomaly where two transactions each read a set of rows, make disjoint writes based on what they read, and together violate an invariant neither could have broken alone.
Write-Ahead Log WAL, Commit Log	concept	Data Architecture	Recording every change to a durable sequential log before applying it, so that a crash can be recovered by replaying the log.
X-Forwarded-For Forwarded Header	concept	Reverse Proxies	The header chain recording original client addresses through a series of proxies — and a value that must never be trusted without knowing the topology.
Zero Trust	concept	Security Architecture	A security model that grants no implicit trust from network position, and authenticates and authorises every request individually.
Zonal vs Regional Services	concept	Availability Zones	Whether a cloud resource lives in one availability zone or is inherently spread across several — a property that determines what a zone failure takes with it.