diff --git a/README.md b/README.md
index d993872..caf3939 100644
--- a/README.md
+++ b/README.md
@@ -14,11 +14,7 @@ TextRender build exports an interface target TextRender::TextRender.
 This means that if TextRender has been installed on the Project Path, it 
 should be enough to do.
 
-translate a string from terminal to the readable form of FLTK . 
-
-  
-
-    
+translate a string from terminal to the readable form of shared memory . 
 
 ## Usage
 
@@ -27,11 +23,15 @@ translate a string from terminal to the readable form of FLTK .
     cmake ..
     make
 
-## Example
+## Description
 
-    TextRenderer textRenderer;
+TextRender has two class, Bitmap class and Font class. 
 
-    string bitmap = textRenderer.translate(testString);
+res/font.bmp (bitmap data, used by Bitmap::load() function)
 
-    textRenderer.outputInscreen(bitmap);
-    
\ No newline at end of file
+res/font.toml (configuration file, it configure how to read the font.bmp)
+
+src/Bitmap class, it used to load the font.bmp file.
+
+src/Font class, it read the font.bmp data by Bitmap class, 
+translate a string to a bitmap
\ No newline at end of file