# Application Scenarios

- Hosting web applications

  You can host web applications and websites in a VPC and use the VPC as a regular network. With EIPs, you can connect ECSs running your web applications to the Internet. A VPN gateway is used to establish a VPN tunnel between the web applications and the service system on the cloud, ensuring high-speed communication between the website and the service system.

- Hosting services that demand high security

  You can create a VPC and security groups to host multi-tier web applications in different security zones. You can associate web servers and database servers with different security groups and configure different access control rules for security groups. You can launch web servers in a publicly accessible subnet, and also run database servers in subnets that are not publicly accessible. In this way, you can ensure high security.

- Extending your corporate network into the cloud

  You can establish a VPN connection between a VPC and a traditional data center to use the ECSs and block storage resources. Applications can be migrated to the cloud and additional web servers can be quickly deployed as needed when there is a spike in demand for computing resources. This way, less money has to be spent on IT and O&M and data is kept safer than in a traditional arrangement. A VPC can span multiple AZs, protecting from single points of failure and ensuring high availability for e-commerce systems.

Parent topic: Service Overview