Wasn't there a type of file that the Master file could read from?

Let’s say I have a scene with an office in there.
But instead of making the furniture and the characters in that Master file, I would like to make an individual file per item. And then “somehow” bring them into the Master file, but still having total dependency on the original file they come from. This way should I need to do modifications I only do them in the original file.
I am pretty sure we used to be able to do this long time ago. I thought it was by Appending things. But it is not doing what I explained above.

Thanks guys

Apparently what I need is Link, instead of Append.