In 1835 Samuel Colt patented the first successful percussion revolver.
Colt, as a teenaged seaman, was inspired by the capstan fixed in the ship, which had a ratchet and pawl mechanism. This mechanism gave him the idea for his improved revolver design.
This is a huge improvement over the earlier prevailed ‘pepper-box revolver’, which is a multiple-barrel firearm, that has three or more gun barrels in a coaxially revolving mechanism.
Each barrel holds a single shot, and the shooter had to manually rotate, yes, the shooter had to manually rotate the whole barrel assembly to sequential index each barrel into alignment with the hammer.
In Colt’s suggestion, the frame of the weapon has a revolving cylinder drilled with several chambers, usually five or six.
The shooter doesn’t need to manually rotate the whole barrel instead the rotation is caused by the action of cocking the hammer with an attached pawl turning the cylinder which is then locked firmly in alignment with one of the barrels by a bolt.
This animation just explains Colt’s invention of the revolving cylinder by pulling the hammer.