What's the difference between "speakers" and "monitors"?

Question

For a small acoustic set up, I would need two small/mid size speakers. So then, what are monitors? Do the monitors require an amp?

Answer 1

In the Studio, Anything on the Floor ( wether a Small or Large Studio) plugged into an AMP or other, was a Speaker ( oddly enough, if an Instrument was a DI to the Desk, anything that was run Parellel to the Input so that the player could hear it like the engineer, was a Monitor ); However, the Sound output in the Studio was usually termed "Monitor".
So, A Speaker can be either items, whilst a Monitor is necessarily a subset of Speaker. In my experience a Monitor had more Variety of Field in one cabinet, where-as a Speaker in this context was usually one type of Speaker ( My Bass Cabinet had either 2 x 26 inch Speakers, or 16 small Size Speakers in two Cabinets in a high resonance Cabinet.
I guess , then, Speakers have More Focus, but Monitors have a multiple roll

Answer 2

Speakers provide sound / noise. eg. speakers

Monitors provide sight / visual. eg. television screen