I thought silencers were a hollywood invention
In USA, at least, "silencer" is the legal term for the device, as used in the National Firearms Act that sets up the regulatory framework.
As to how much relation the Hollywood type has to the real thing, it depends on the specific depiction and the specific real thing. Modern efficient suppressor designs combined with subsonic ammunition that is specifically designed to be suppressed can be pretty damn quiet, especially out of longer barrels where pressure is lower at the muzzle, and in bolt-action or other manual action firearms where the action itself doesn't make any noise during firing.
You can actually kinda sorta get that IRL sometimes, with a sufficiently powerful laser (which rifle laser sights often are), because it will light up the dust in the air, or particles of water when it's humid (esp. outside).