Both really. It would depend upon, what, location and weight. The number of sheeves in a block determined the ease of moving the weight. For example, a block with four sheeves made lifting heavy rigging much easier while lifting the same with a block half the size, or two sheeves was very difficult. Blocks, sheeves, bitts, and capstans were all placed depending on what needed to be moved around...and remember most movement was done under sail...or under stress. So what might be easy sitting in port was exceedingly more difficult under sail. Most movement needed to be done quickly so the rigging was set to aid "by hand" movement as it was clumsy to run a line to the capstan quickly. So the answer lies in what needs to be lifted, or hauled, and what combinations of block and tackle was necessary to do it. Then the power came from one or more "hands."
@danielsje Thank you sir. Very all round answer! Listening to all that, yes it all makes sense. The need designated what tools and when to be used.