add introductions of commands to key-concepts.mdx

Signed-off-by: Eric Fu <[email protected]>

reference/key-concepts.mdx

@@ -113,6 +113,22 @@ Protocol buffers (commonly known as Protobuf) are Google's language-neutral, pla
 
 `psql` is a terminal-based front-end to PostgreSQL and other databases that are compatible with the PostgreSQL [wire protocol](#wire-protocol), such as RisingWave. With `psql`, you can type queries interactively, issue these queries to RisingWave, and see the query results. In addition, `psql` provides a number of meta-commands and various shell-like features to facilitate writing scripts and automating a wide variety of tasks.
 
+### `risectl`
+
+`risectl` is a command-line tool designed to manage the RisingWave kernel. It offers functionalities to inspect the cluster status and provides access to low-level APIs for cluster control. This tool is included with each [version release](https://github.com/risingwavelabs/risingwave/releases/). Please use it at your own risk. Run `risectl help` for more details.
+
+### `risedev`
+
+`risedev` is a command-line utility that aids in the development of RisingWave. It is built on `cargo-make`, a crucial tool for building Rust projects. `risedev` is included as part of RisingWave's source code. Additionally, `risectl` is integrated into `risedev` as a subcommand, `risedev ctl`.
+
+### `risingwave`
+
+`risingwave` is the standalone binary for the RisingWave database. Different nodes are initiated through subcommands; for instance, `risingwave compute-node` launches the compute node. Run `risingwave help` for more details. `risectl` is also incorporated into `risingwave` as a subcommand, `risingwave ctl`. 
+
+### `rwc`
+
+`rwc` (RisingWave Cloud CLI) is a command-line tool used to access and manage RisingWave Cloud/BYOC instances via open APIs. It is particularly essential for [setting up the BYOC cluster](https://docs.risingwave.com/cloud/project-byoc#create-a-byoc-environment). For more information, please refer to [this document](https://github.com/risingwavelabs/risingwave-cloud/blob/main/cli/README.md#installation).
+
 ### Serialization[](#serialization "Direct link to Serialization")
 
 In stream processing, serialization is the process of converting business objects into bytes so that they can be easily saved or transmitted. The reverse process, recreating the data structure or object from a stream of bytes, is called deserialization. Common data serialization formats include JSON, [Avro](#avro), Protobuf (protocol buffers), and CSV.