Reading from my Haynes manual for '82 thru '94 S-10/S-15 family says the following:
Clutch cable system applies to '82 and '83 years only.
A hydraulic clutch assembly applies to all '84 and later years and consists of a remote reservoir usually mounted on the firewall, a master cylinder mounted on the firewall (lower) and a release or "slave" cylinder mounted on the transmission.
Pressing on the clutch pedal pushes on a rod that connects to the master cylinder causing fluid to be forced thru a connecting fluid line to the release cylinder causing the release cylinder to extend a rod that in turn pushes against the clutch release lever resulting in the release of the clutch via the throw out bearing.
Sounds complicated but easier to understand if you could see a diagram. All such clutch systems pretty much the same way.