Deploying

Getting it in front of people.

Static and dynamic

A static site is files on a server or a CDN: cheap, fast and hard to break. A dynamic site runs code per request and needs somewhere for that code to live.

HTTPS is not optional; certificates are free and automatic now.
Set cache headers deliberately, or returning visitors will run old code.

After launch

Watch for errors in the browser as well as on the server, since most failures happen on devices you do not own. A simple error report from real users beats any amount of local testing.