PuTTY is a free command line tool and software application for Windows 95, 98, XP, Vista, and 7 & 8 which can be used to make an SSH connection to your server. You can download the application (download putty.exe or putty.zip) at http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html. PuTTY comes bundled with command-line SCP and SFTP clients, called "pscp" and "psftp" respectively.
First Time Connecting to your Server
Your server might be located thousands of miles away from you. However, with the help of a couple of programs, you can connect to it as if it were in front of you. And most importantly, all of these programs allow you to connect safely to your server through what is called 'SSH'.
What is SSH?
SSH (Secure Shell) is a network protocol used for secure data communication between a server and a client (You) to perform (for example: command-line login and authentication, remote command execution, and even data transfer). So in order to keep the communication between you and a server secure from the preying eyes of hackers, there are programs that implement SSH protocols mainly by using strong encryption methods to help you achieve that
To establish communication between a client and a server, you must have SSH program on each communicating end. Hence come OpenSSH and PuTTY, which are only two SSH programs from several others. OpenSSH is the most popular and most widely used SSH program that comes shipped with Ubuntu Operating system. You do not need to install it. PuTTY is the most popular SSH program in Windows OS. You need to install Putty on your Windows PC. In this tutorial, I will explain how to use them correctly in order to communicate securely with your server.
Installing and Configuring PuTTY in Windows
Since OpenSSH is already installed on our server, you only need to install PuTTY before you can connect to your server. Go to PuTTY's official download page from here and download the installer file which looks like [putty-x.xx-installer.exe]. After downloading it, install as you would install any Windows program; just make sure to install it only for the current user, especially if your PC is used by many users. Once the install is finished, launch PuTTY and a configuration window will appear to you
In the Host Name (or IP address) field, enter your server IP address, which you can get from the email that you have received once the server is created or in your client control panel.
Just make sure that the Port field shows number 22; since it's the default port number for SSH protocol, and also the Connection type set to SSH as in
In the Saved Sessions field, write a name for your session and then hit SAVE; this will save all the configurations we did earlier; so that the next time you launch PuTTY, you wouldn't have to enter your server's configuration and your PuTTY preferences all over again.
Finally you are ready to connect to your server, either by selecting the session name and then clicking the Open button at the bottom or simply double-clicking the session name that you have saved earlier.
You'll notice that the configuration window disappeared and instead a black terminal window has appeared but with a 'Security Alert'. assuming you have entered your server's IP address or host name correctly, it would be safe now to click 'Yes'. What that basically does is tell PuTTY to save your server's Host key in its known hosts database in windows registry to be used for future authentications.
Finally, server authentication is completed and secure connection is established.
Since you are finally connected securely to your sever, it is safe now to send your login credentials through the SSH encrypted connection. You can get your primary login credentials from the email that you have received once the droplet is created. The picture below shows a terminal command line where you are going to enter your username in the line that says login as:, then hit Enter, then a new line will appear asking for your password, type it and hit Enter.
While entering your password, you will notice that the cursor in the command line is not moving or displaying any asterisk. Don't worry even though nothing seems to appear on the command line as you type, every key you press on your keyboard is actually being entered and sent to your server. And that's the default behavior in all Linux distro regarding password submission.
You will know that the client authentication process was successful when the terminal shows you brief information about the Linux distribution that is installed on your server, information about the last time you logged in, and the last line is where all the magic happens and it's called the 'Command or Prompt line', and its structure is similar to the following:
username@hostname:~# "example: root@host123:~#"
The first part indicates the username that you are currently logged in as then the host name, separated by the '@' symbol, followed by your current directory (in this example ~, which refers to current user home directory) and the hash sign indicates the end of command line.