diff --git a/glossary/CORS.md b/glossary/CORS.md
new file mode 100644
index 000000000..e211f8c1f
--- /dev/null
+++ b/glossary/CORS.md
@@ -0,0 +1,3 @@
+### CORS
+
+Cross-Origin Resource Sharing (known as CORS) is a mechanism that uses extra HTTP headers to tell a browser to let a web application running at one domain have permission to access resources from a server at a different domain.