diff --git a/README.md b/README.md
index cbc25e7..c788800 100644
--- a/README.md
+++ b/README.md
@@ -1,17 +1,73 @@
-# ext-helloworld
+# HelloWorld PHP Extension
 
-## Install
+[![Build and Test PHP Extension](https://github.com/koriym/ext-helloworld/actions/workflows/build.yml/badge.svg)](https://github.com/koriym/ext-helloworld/actions/workflows/build.yml)
 
-```sh
-# git clean -fd
-# phpize --clean
-phpize
-./configure
-make
-```
+A simple PHP extension that demonstrates basic and advanced "Hello World" functionality.
+
+## Features
+
+- Basic `helloworld()` function
+- Advanced `helloworld_advanced()` function with configurable greeting
 
 ## Run
 
-```sh
-php -dextension=helloworld.so helloworld.php
+1. Compile the extension:
+
+    ```
+    // make clean
+    // phpize --clean
+    phpize
+    ./configure --enable-helloworld-advanced
+    make
+    ```
+
+2. Run
+
+    ```
+    % php -d extension=./modules/helloworld.so -i | grep hello
+
+    helloworld
+    helloworld support => enabled
+    helloworld.greeting => Hello World! => Hello World!
+
+    % php -d extension=./modules/helloworld.so php/helloworld.php
+    Hello World!
+    Hello World!
+   ```
+
+## Usage
+
+### Basic Function
+
+```php
+<?php
+helloworld();
+// Output: Hello World!
 ```
+
+### Advanced Function
+
+```php
+<?php
+helloworld_advanced();
+// Output: [Configurable greeting from php.ini]
+
+```
+
+To configure the greeting, add the following to your php.ini:
+
+```
+helloworld.greeting = "Your custom greeting!"
+```
+
+## Build script
+
+You can use the build.sh script for various build operations:
+
+```sh
+./build.sh clean   # Clean the build environment
+./build.sh prepare # Prepare the build environment
+./build.sh build   # Build the extension
+./build.sh run     # Run the extension
+./build.sh all     # Execute all the above steps
+```
\ No newline at end of file