What is the difference between an assembly line and a manufacture?

In an assembly line, the product moves, so at one station, a worker adds the same part to every item. This is assembly line manufacturing (as pioneered by Henry Ford). This scheme affords a company the option of manufacturing many similar items efficiently.

An example of pure manufacture is the construction of an airplane, where different sections of the airplane are brought to a single spot and added to the ship. A worker may weld or fit in all the variable parts in several sections. This scheme affords a company the option of manufacturing a single item efficiently, especially one with multiple thousands of parts.