sshhhhhhh. Lets talk about this fancy little term called "ssh". What exactly is ssh and what does it do? ssh stands for Secure Shell, and it is essentially a protocol used in order for two devices to talk to each other or communicate with each other. It is called "secure shell" because this protocol uses strong encryption to allow safe communication between a client and a server. So for example, you can basically connect to a computer (server) remotely by using this protocol. It is used for logging into computers over the internet, and to communicate with them (execute commands) to transfer data (such as files, or important information)--although this is just one function out of many other uses!! Every time you "ssh" into something, you are accessing that computer/server over the network. You can connect to a server via a particular terminal (like Terminal in macOS, PuTTY..etc.) and the SSH protocol!! The procedures usually vary from terminal to terminal but if you type in ssh into any particular terminal, it should give you a list of options (flags) you can use to connect to a server. These options or flags specify certain restrictions that the protocol needs to apply. For example the ssh -4 options enables ssh to use only IPv4 addresses. The -6 flag uses IPv6 addresses. The -i flag tells ssh that there is an "identity file" (such as a private key) which authenticates the user to communicate with the server. How does it work??When you establish a connection to a remote server, by using the ssh protocol (typing the command into the terminal and setting the destination server host name), there are 2 steps that help the client/server verify and prove their identity to each other. The client needs to make sure its accessing the right ssh server, therefore, when the client initiates a connection with the server, the server verifies its identity to the client. Then, the user/client verifies that they are authorized to access the server (User authentication). This is obviously a very high level approach of understanding ssh, there are many many tiny details the ssh protocol involves (such as public key authentication). I'll get into that more on later, but for now, GOOD LUCK :)
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