[Webdev] very poor html q

[MC]

I will try to get this one in quick while the list is new! (but it has me stuck a while). Maybe just html.
Is there an easy way to get a page to pull in another file (like maybe to put
something like a sig at the bottom of every page, rather than inserting it
into every .html file)? This occurred to me while trying to access a script
(e.g. to print time and date/counter), but without typing the script in every
page. I can see how to include jpgs, and so forth... but text has me stumped.
hope this doesn't lower the tone too much,
TIA
mick