What is the Droplet Hostname?

Think of it in this context:<br/><br/>Imagine a large [western] family. Instead of humans, however, picture a cluster of computers. Just as every person in a family has a common last name and a different first name…<br/><ul><li>hostname is to domain name (in the networking world) as a person’s first name is to that person’s lastname/family-name.</li> <br></ul>Have you ever heard the saying, <b>Don’t put all your eggs in one basket</b>? Among other reasons, a computer admin. may wish to distribute various tasks across multiple (cloud) servers, e.g. pop.yourdomain.tld; smtp.yourdomain.tld; www.yourdomain.tld; cdn.yourdomain.tld; ns1.yourdomain.tld; ns2.yourdomain.tld; loadbalancer1.yourdomain.tld; loadbalancer2.yourdomain.tld; and so on.<br/><br/>In this example, the <b>xxx</b> in <b>xxx.yourdomain.tld</b> is the hostname. Where you’re getting confused, I believe, is that every host, e.g. cdn.yourdomain.tld, can have more than one hostname (or, host alias); hence, why you often see the reference to <b>localhost</b> on EVERY computer or cloud instance.<br/><br/>Our friends @ Google are also usually very helpful with questions such as this.

Think of it in this context:<br/><br/>Imagine a large [western] family. Instead of humans, however, picture a cluster of computers. Just as every person in a family has a common last name and a different first name…<br/><ul><li>hostname is to domain name (in the networking world) as a person’s first name is to that person’s lastname/family-name.</li> <br></ul>Have you ever heard the saying, <b>Don’t put all your eggs in one basket</b>? Among other reasons, a computer admin. may wish to distribute various tasks across multiple (cloud) servers, e.g. pop.yourdomain.tld; smtp.yourdomain.tld; www.yourdomain.tld; cdn.yourdomain.tld; ns1.yourdomain.tld; ns2.yourdomain.tld; loadbalancer1.yourdomain.tld; loadbalancer2.yourdomain.tld; and so on.<br/><br/>In this example, the <b>xxx</b> in <b>xxx.yourdomain.tld</b> is the hostname. Where you’re getting confused, I believe, is that every host, e.g. cdn.yourdomain.tld, can have more than one hostname (or, host alias); hence, why you often see the reference to <b>localhost</b> on EVERY computer or cloud instance.<br/><br/>Our friends @ Google are also usually very helpful with questions such as this.

A droplet/server’s hostname is basically its name. You can name it anything you want, such as your domain name or the name of a Greek god ;) <br> <br>Your IP’s PTR/rDNS record is set to your droplet’s hostname so if you’re going to run a mailserver you have to set it to your FQDN.

For me, the public IP was the hostname. I used it to find the “host” “hash” with: ssh-keygen -H -F <my.ip.was.here>

can I use the same hostname for different droplets?

When using a FQDN do you also need to create an A record for the name that you pick?

Thanks pablo for your detailed answer … You are really good it helped me alot .