Explaining different outage types in Temporal Cloud

docs/cloud/high-availability/failovers.mdx

@@ -150,7 +150,7 @@ At any time only the primary or the replica is active.
 The only exception occurs in the event of a [network partition](https://en.wikipedia.org/wiki/Network_partition), when a Network splits into separate subnetworks.
 Should this occur, you can promote a replica to active status.
 **Caution:** This temporarily makes both regions active.
-After the network partition is resolved and communication between the isolation domains/regions is restored, a conflict resolution algorithm determines whether the primary or replica remains active.
+After the network partition is resolved and communication between the regions is restored, a conflict resolution algorithm determines whether the primary or replica remains active.
 
 :::tip
 
@@ -289,7 +289,7 @@ See [Returning to the primary with failbacks](#failbacks) for details on how and
 
 After any failover, whether triggered by you or by Temporal, an event appears in both the [Temporal Cloud Web UI](https://cloud.temporal.io/namespaces) (on the Namespace detail page) and in your audit logs.
 The audit log entry for Failover uses the `"operation": "FailoverNamespace"` event.
-After failover, the replica becomes active, taking over in the isolation domain or region.
+After failover, the replica becomes active, taking over from the original region.
 
 You don't need to monitor Temporal Cloud's failover response in real time.
 Whenever there is a failover event, Temporal Cloud [notifies you via email](/cloud/notifications#admin-notifications)
@@ -405,14 +405,14 @@ Failover testing (also known as "<ToolTipTerm term="trigger testing" />)" can:
 
 - **Validate replicated deployments**:
   In multi-region setups, failover testing ensures your app can run from another region when the primary region experiences outages.
-  In standard setups, failover testing instead works with an isolation domain.
+  In Same-region Replication setups, failover testing instead works with a separate cell within the same region.
   This maintains high availability in mission-critical deployments.
   Manual testing confirms the failover mechanism works as expected, so your system handles incidents effectively.
 
 - **Assess replication lag**:
   In multi-region deployment, monitoring [replication lag](/cloud/metrics/openmetrics/metrics-reference#temporal_cloud_v1_replication_lag_p99) between regions is crucial.
   Check the lag before initiating a failover to avoid rolling back Workflow progress.
-  This is less important when using isolation domains as failover is usually instantaneous.
+  This is less important with Same-region Replication, as failover is usually instantaneous.
   Manual testing helps you practice this critical step and understand its impact.
 
 - **Assess recovery time**:

docs/cloud/high-availability/index.mdx

@@ -20,8 +20,12 @@ keywords:
 
 import { ToolTipTerm, DiscoverableDisclosure, CaptionedImage } from '@site/src/components';
 
-Temporal Cloud's High Availability features use asynchronous <ToolTipTerm term="replication"/> across multiple <ToolTipTerm term="isolation domains" /> to provide enhanced resilience and a 99.99% [SLA](/cloud/sla).
-When you enable High Availability features, Temporal deploys your primary and its <ToolTipTerm term="replica"/> in separate isolation domains, giving you control over the location of both. This redundancy, combined with <ToolTipTerm term="failover"/> capability, enhances availability during outages.
+Temporal keeps your Workflows running even when a Worker crashes. But what happens when a whole data center crashes? Or a region?
+
+In the cloud, outages are commonplace. An outage can bring down a whole data center, cluster, region, or cloud provider. To be durable in the cloud, Workflows and applications must handle these outages smoothly, just like Temporal handles a Worker crash.
+
+Temporal Cloud's High Availability features add extra reliability to Temporal Cloud Namespaces by handling cloud outages. Using asynchronous <ToolTipTerm term="replication"/> between multiple regions or cloud providers, combined with automatic outage detection and failover, High Availability keeps your Workflows running even during a cloud region outage.
+This extra availability comes with an enhanced [SLA](/cloud/sla) of 99.99%, _including_ cloud provider outages.
 
 :::tip White paper
 
@@ -34,7 +38,7 @@ For an in-depth guide covering everything from why you need High Availability to
 Even without High Availability features, Temporal Cloud provides robust reliability and a 99.9% contractual Service Level Agreement ([SLA](/cloud/sla)) guarantee against service errors.
 
 Each standard Temporal Namespace uses replication across three [Availability Zones](https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/using-regions-availability-zones.html#concepts-availability-zones) (AZs) to ensure high availability.
-An Availability Zone is akin to an isolated datacenter managed by a cloud hyperscaler, with independent power, networking, and cooling infrastructure.
+An Availability Zone is akin to an isolated data center managed by a cloud hyperscaler, with independent power, networking, and cooling infrastructure.
 
 Replication across AZs makes sure that any changes to Workflow state or History are saved in all three AZs _before_ the Temporal Service acknowledges a change back to the Client.
 As a result, your standard Temporal Namespace stays operational even if one of its three AZs becomes unavailable.
@@ -44,7 +48,7 @@ However some critical use cases--such as customer-facing applications--require e
 
 ## High Availability features {#high-availability-features}
 
-High Availability features extend Temporal Cloud's replication offering across even more disparate isolation domains:
+High Availability features extend Temporal Cloud's replication across regions and cloud providers, so your Namespace keeps running even when a whole region or cloud provider goes down:
 
 | **Deployment**                          | **Description**                                            |
 | --------------------------------------- | ---------------------------------------------------------- |
@@ -53,7 +57,7 @@ High Availability features extend Temporal Cloud's replication offering across e
 
 ### Key features
 
-- **Real-time replication** — Temporal replicates your Namespace across distant isolation domains with no performance impact to your Workers or Workflows.
+- **Real-time replication** — Temporal replicates your Namespace across distant regions or cloud providers with no performance impact to your Workers or Workflows.
 - **Automatic failover with 20-minute RTO** — Temporal manages failover with a 20-minute [RTO](/cloud/rpo-rto). You can also [trigger failover](/cloud/high-availability/failovers) manually at any time, for example for testing.
 - **Transparent DNS routing** — On failover, DNS reroutes your [Namespace Endpoint](/cloud/namespaces#access-namespaces) to the active region. Requests that reach the replica are forwarded to the active region automatically.
 - **Sub-1-minute RPO** — In a failover during an outage, the [Recovery Point Objective](/cloud/rpo-rto) is under one minute.
@@ -63,10 +67,10 @@ High Availability features extend Temporal Cloud's replication offering across e
 :::info Region availability
 
 You can usually choose your replica region, but the replica must be on the same continent as the primary region.
-This means that a few Temporal Cloud regions do not yet support Multi-region Replication and/or Multi-cloud Replication.
+This means that a few Temporal Cloud regions do not yet support Multi-region Replication or Multi-cloud Replication.
 See [Regions](/cloud/regions) for a full list of supported replica regions.
 
-You can't enable both Multi-region Replication and Multi-cloud Replciation on the same Namepsace at the same time.
+You can't enable both Multi-region Replication and Multi-cloud Replication on the same Namespace at the same time.
 
 :::