Need someone to explain to me what these connectors are on the back of my "Eclipse"

[Plugedearz]

ok i have an Eclipse headr unit model 5411 & i dont know what these connectors are for on the back of my radio, also i have JL audio amps (500/1) & they have this connector thing on the back that looks like a can plug a phone cord into it so please tell me what this is for

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[mstrblk 10+ year member]

most likley the plug on the back of your hu is for either a changer, and/or the compatable dsp/eq, as for the amp, it is most likley a connector for a remote bass boos adjustment, but the manufacturerers websites would have the info