diff --git a/license.txt b/license.txt
new file mode 100644
index 0000000..7bd9649
--- /dev/null
+++ b/license.txt
@@ -0,0 +1 @@
+2022/5/18
\ No newline at end of file
diff --git a/readme.txt b/readme.txt
index 99e0e11..f21047c 100644
--- a/readme.txt
+++ b/readme.txt
@@ -1,2 +1,3 @@
 Git is a distributed version control system.
-Git is free software distributed under the GPL.
\ No newline at end of file
+Git is free software distributed under the GPL.
+Git has a mutable index called stage.
\ No newline at end of file