ubuntu的问题

暂时不想管，先弄一个凑合用的blog

Introduction to Cloud Servers
Because a cloud server is effectively a whole virtual computer, other cloud product offerings can be understood in relation to them. 

云服务器本质上是提供了一台公网地址下的远程电脑。cloud servers will always be running as virtual machines

To understand cloud servers, it's helpful to understand the type of software that runs in the cloud.Today, nearly all cloud customers use a Linux-based operating system

Server-side software: This is a class of software that’s designed to run in a cloud environment, which does not have a desktop environment or a display connected to it. Usually, this means that the software is installed and configured via a command line interface, and then accessed by regular users through a web browser or another application.

Web servers: This software enables your cloud server to communicate with users or applications on the internet using the HTTP protocol. 

API servers: APIs (Application Programming Interfaces) are a type of software mediary that enable applications to communicate with one another.

Database servers: Database servers, also called databases, are another type of API server. Unlike web servers, which can be accessed via a web browser and usually render an HTML interface, database servers are usually accessed via a database query API.

which will typically still involve virtualized server clusters, but the principle is consistent. The primary distinction is that a cloud server (sometimes called a VPS, or virtual private server, to clarify that it is a virtual machine) can be made to run any software in any way, whereas any other cloud offering is effectively an optimized and constrained subset of server features.

Should I Use a Cloud Server?

It is often sufficient to deploy a firewall like ufw that can expose network ports on an individual basis to keep a server secure, or to at least offload the responsibility for that security to the maintainers of software like Nginx, which is used on millions of servers worldwide.

Access

To connect and work with cloud servers, you will need to know how to work in a terminal environment, both locally and remotely. Remote terminal connections mostly make use of a protocol called SSH, or Secure Shell.Along with HTTP, this is one of the most commonly used protocols, although SSH is naturally used more often by administrators rather than end users. HTTP runs on port 80 (and port 443 for HTTPS). SSH typically runs on port 22. Cloud administration can be broadly understood in terms of these protocols, servers, and services.