Learn Italian: Se vedi il link per il database, cliccaci subito! - If you see the link for the database, click on it immediately!

It means "on it." In Italian, "to click on" is cliccare su. Instead of repeating the noun and saying clicca sul link (click on the link) or clicca su di esso (click on it), we use the clitic ci to replace su + the object.

Why is ci attached to the end of the verb instead of coming before it?

Because clicca is an affirmative imperative (a direct command). In Italian, pronouns and clitics like ci must be attached to the end of affirmative commands. If this were a regular statement like "you click on it," the ci would go before the conjugated verb: tu ci clicchi.

Is cliccare treated just like a normal Italian verb, even though it's borrowed from English?

Exactly! When Italian adopts English verbs, it usually adds an -are ending and treats them perfectly regularly. So, the informal command "click!" is clicca!, following the exact same pattern as parla! (speak!) or guarda! (look!).

Why are link and database masculine (il link, il database)?