| --- |
| id: concepts-overview |
| title: Pulsar Overview |
| sidebar_label: "Overview" |
| description: Key features of Pulsar. |
| --- |
| |
| Pulsar is a multi-tenant, high-performance solution for server-to-server messaging. Originally developed by Yahoo, Pulsar is under the stewardship of the [Apache Software Foundation](https://www.apache.org/). |
| |
| ## Key features |
| |
| Key features of Pulsar are listed below: |
| |
| * Native support for multiple clusters in a Pulsar instance, with seamless [geo-replication](administration-geo.md) of messages across clusters. |
| * Very low publish and end-to-end latency. |
| * Seamless scalability to over a million topics. |
| * A simple [client API](concepts-clients.md) with bindings for [Java](client-libraries-java.md), [Go](client-libraries-go.md), [Python](client-libraries-python.md) and [C++](client-libraries-cpp.md). |
| * Multiple [subscription types](concepts-messaging.md#subscription-types) ([exclusive](concepts-messaging.md#exclusive), [shared](concepts-messaging.md#shared), and [failover](concepts-messaging.md#failover)) for topics. |
| * Guaranteed message delivery with [persistent message storage](concepts-architecture-overview.md#persistent-storage) provided by [Apache BookKeeper](http://bookkeeper.apache.org/). |
| A serverless lightweight computing framework [Pulsar Functions](functions-overview.md) offers the capability for stream-native data processing. |
| * A serverless connector framework [Pulsar IO](io-overview.md), which is built on Pulsar Functions, makes it easier to move data in and out of Apache Pulsar. |
| * [Tiered Storage](tiered-storage-overview.md) offloads data from hot/warm storage to cold/long-term storage (such as S3 and GCS) when the data is aging out. |
| |
| ## Contents |
| |
| - [Messaging Concepts](concepts-messaging.md) |
| - [Architecture Overview](concepts-architecture-overview.md) |
| - [Pulsar Clients](concepts-clients.md) |
| - [Geo Replication](concepts-replication.md) |
| - [Cluster-level failover](concepts-cluster-level-failover.md) |
| - [Multi Tenancy](concepts-multi-tenancy.md) |
| - [Authentication and Authorization](concepts-authentication.md) |
| - [Topic Compaction](concepts-topic-compaction.md) |
| - [Message throttling](concepts-throttling.md) |
| - [Proxy support with SNI routing](concepts-proxy-sni-routing.md) |
| - [Multiple advertised listeners](concepts-multiple-advertised-listeners.md) |
