Speakers connect to an amp with a two conductor speaker cable. The connections at the ends depends on what equipment and speakers you have. Wire with bare ends is most common. You can use spade lugs or banana plugs with most amps and speakers, Some cheaper speakers use RCA jacks. Speakers from home theater package systems often have oddball connectors but the wire is still two conductor. You can cut off the connector at the end and strip the wire. It is important to get the polarity right (+ to + and - to -) if you get it wrong the bass will go away.
Aux cord would be what connects the amp to the source or preamp. Most amps have 2 RCA jacks as inputs. Some will also have 3.5mm stereo mini jack as input. Cables are available that have 2...