When buying a set of good speakers and a quality amplifier, it is important to use the right cables. You do not have to spend a lot of money on cables, but a solid and correct connection is needed to maximize your benefit from your equipment. The most common audio cables are 3.5 mm mini jack, RCA or TOSLINK.
Mini jack is the standard within everything from smartphones and tablets to laptops and MP3 players. The cable is a smaller version of the 6.35 mm jack cable and is also known as the AUX cable. The mini jack cable is available in many different lengths and if you are missing an adapter, there are both splitters and converters for RCA.
With an amplifier or AV receiver, it would be natural to use a copper speaker cable, RCA or TOSLINK cable. If you have passive speakers, you would usually need a copper cable. If you use active speakers, you would often use an RCA, TOSLINK (SPDIF) or AUX cable.