Static site
A static site is made of ready files that are sent as they are, with nothing built when a visitor arrives.
In a simple example
A menu page with fixed text and pictures is static. The host just hands over the files.
Why it matters to you
Static sites are fast, cheap to host and hard to break into, which suits most small businesses.
Do not confuse with
Static does not mean boring. It can still have moving effects and forms that send to another service.