grammer correction

Author: teresayao

articles/web-application-firewall/overview.md

@@ -21,10 +21,10 @@ A WAF solution can  react to a security threat faster by centrally patching a kn
 
 ## Supported service
 
-WAF can be deployed with Azure Application Gateway,  Azure Front Door and Azure Content Delivery Network (CDN) service from Microsoft. WAF on Azure CDN is currently under public preview.  WAF has features that are customized for each specific service. For more information about WAF features for each service, see the overview for each service.
+WAF can be deployed with Azure Application Gateway,  Azure Front Door, and Azure Content Delivery Network (CDN) service from Microsoft. WAF on Azure CDN is currently under public preview.  WAF has features that are customized for each specific service. For more information about WAF features for each service, see the overview for each service.
 
 ## Next steps
 
 - For more information about Web Application Firewall on Application Gateway, see [Web Application Firewall on Azure Application Gateway](./ag/ag-overview.md).
-- For more information about Web Application Firewall on Azure Front Door Service see [Web Application Firewall on Azure Front Door Service](./afds/afds-overview.md).
-- For more information about Web Application Firewall on Azure CDN Service see [Web Application Firewall on Azure CDN Service](./cdn/cdn-overview.md)
+- For more information about Web Application Firewall on Azure Front Door Service, see [Web Application Firewall on Azure Front Door Service](./afds/afds-overview.md).
+- For more information about Web Application Firewall on Azure CDN Service, see [Web Application Firewall on Azure CDN Service](./cdn/cdn-overview.md)