Components specific to the page - How?

[Timbow]

I know I have seen somewhere how to do this but can't find the info - to have a different component on a different page without making a new page template.

To be clear, what I am trying to do is to put a mini thumbnail gallery in the sidebar with i18n galleries, but on the page 'Sheep' I want the gallery of sheep, on the page 'Goats' I want the goat gallery and on Home I don't want any gallery at all; so I will have different components for the different sidebar contents, and I want them to appear on the right pages