In one sentence, describe what the following article is about:

Minecraft has an icon that resembles a grass block.  Click it on your desktop or Windows Start menu to launch Minecraft. It's the first button on the Minecraft title screen. It's the third tab at the top of the Play menu. It's the same name you gave your server at the top of the server.properties file. You can find your external IP address by going to https://www.whatismyip.com/ in a web browser.  Anyone who wants to connect to your server can use your external IPv4 address to connect to it. The default port number for most Minecraft servers is 19132.  If you are using Port Forwarding, you may have a different IP address. This saves your server to your server list. Your server should be listed below "More Servers" at the bottom of the servers listed in the "Servers" tab.  Click your server to connect to it. It may take a while to connect the first time you connect to it.

Summary:
Open Minecraft. Click Play. Click Servers. Enter your server name at the top. Enter your external IP address. Enter your port number. Click Save. Click your server.